Associations Between Deer Browse and Aphid Colonization in a Long-Term Monitoring Study of Liguisticum porteri - S. Rittler (2024)
Deer are prolific herbivores that, if left to increase exponentially, could decimate populations of plants and possibly other herbivores. Due to the rapidly increasing abundance of deer, this is a risk that is getting ever closer to becoming a reality. This phenomenon is a concern for herbivores that currently share plant resources with deer species, as well as the plants that deer rely on for food. Many herbivores that are at risk of this competition are insects. Insect populations are already decreasing, but with the addition of increased deer abundance and, thus, increased competition around the corner, it is more important than ever to understand how these organisms interact. This study explores the ecological and trophic relationships between mule deer (Odocoileus hemionus) and aphid colonies (Aphis asclepiadis) on the plant Osha (Ligusticum porteri) and the possibility that deer are seeking out aphid colonized plants as a food source. If this is the case, the insects could be at risk of this resource competition that could eventually have devastating effects on their populations. Mule deer populations can be controlled on the local level, and this study will inform what organisms are being effected by large herbivores and whether population management may be needed for these herbivorous mammals.

The Power of Playing with Genre: The Western Gothic Melodrama in Jane Campion’s The Power of the Dog (Netflix, 2021) - Hervé Mayer (SPIRE - Sciences Po Institutional REpository, 2024)
International audience

The Impact of Delphinium nuttallianum and Ipomopsis aggregata Phenology on Broad-tailed Hummingbird (Selasphorus platycercus) Visitation Patterns - L. Granier (2024)
Biological interactions reliant on synchronized phenology are being thrown into disarray with warming temperatures and an earlier onset of spring. Migrating Broad-tailed Hummingbirds (Selasphorus platycercus) in Gothic, Colorado tend to arrive and breed in alignment with wildflower flowering phenology, fostering important plant-pollinator interactions. Two wildflower species, Delphinium nuttallianum and Ipomopsis aggregata, form a large part of the hummingbirds’ diet and bloom in sync with arrival and breeding milestones. Since both hummingbirds and wildflowers benefit from a synchronized schedule, phenological mismatch would likely decrease hummingbird population persistence through food resource limitation. For this project, we investigated whether weekly changes in Broad-tailed Hummingbird wildflower visitation patterns correspond to changing wildflower phenology in 2022, an earlier-than-average snowmelt year, and 2023, a later-than-average snowmelt year. Due to climate change, years like 2022 with earlier snowmelt are expected to become more common. Using floral phenology transect data and hummingbird visitation data for D. nuttallianum and I. aggregata, we determined that Broad-tailed Hummingbirds adjust their foraging behavior to align with the phenology of their food sources, a behavior that may help prevent the phenological mismatches projected to occur with climate change.

Feral Hues & Invasive Pigments: Examining Nature-Based Solutions through Ecosocial Art Engaging Spontaneous Urban Vegetation and Informal Greenspace - E. Irons (Nature-Based Solutions, 2024)
The project Feral Hues and Invasive Pigments (FH&IP) addresses the role of spontaneous urban plants (aka weeds) through ecosocial art, with the goal of reducing human alienation from plant life and land in urban and disturbed habitats. Hands-on work with spontaneous urban plants through ecosocial artistic methods—like walks, workshops, and land-based sculptures—provides cues for understanding weedy plants and informal greenspace (IGS) as part of nature-based solutions (NBS) in cities. In dialog with NBS research that takes a justice-oriented, degrowth approach to urban greenspace, the FH&IP project invites hands-on, hyperlocal participation of humans and plants at the neighborhood level to enhance the role of low maintenance IGS. Bringing ecosocial artistic methods into conversation with NBS research is one way to open up knowledge practices that inform both fields. Multisensorial, direct engagement with urban-dwelling plants can help practitioners and participants understand what kinds of maintenance and tending might help improve sentiment around spontaneous urban vegetation and improve its functional benefits for human communities. In the right context, such benefits range from flood mitigation to improved mental health to cooler, cleaner air. A “ladder of engagement” for reciprocal exchange with spontaneous urban plants is proposed to trace how the ecosocial artistic methods employed in FH&IP build plant-human solidarity towards more functional NBS in IGS. Methods like gallery installations, workshops, and walks are described and analyzed for their strengths and weaknesses in accessibility and depth, qualities that help initiate engagement and move participants up the ladder. At the lowest rung of the ladder, participants ignore or actively harm spontaneous urban plants, then move to noticing, tending, and eventually advocating for plants and the land they dwell on. The shift from alienation to advocacy has potential to improve the function of IGS by amplifying and enhancing contextually appropriate NBS that respect local needs and desires while improving equitable distribution of bioculturally diverse greenspace.

Spatially distributed snow depth, bulk density, and snow water equivalent from ground-based and airborne sensor integration at Grand Mesa, Colorado, USA - Kelly Elder; Ryan W. Webb; Randall Bonnell; Elias J. Deeb; Shad O'Neel; Ahmad Hojatimalekshah; Christopher Hiemstra; Hans-Peter Marshall; Tate G. Meehan; Mark S. Raleigh (The Cryosphere, 2024)
Abstract. Estimating snow mass in the mountains remains a major challenge for remote-sensing methods. Airborne lidar can retrieve snow depth, and some promising results have recently been obtained from spaceborne platforms, yet density estimates are required to convert snow depth to snow water equivalent (SWE). However, the retrieval of snow bulk density remains unsolved, and limited data are available to evaluate model estimates of density in mountainous terrain. Toward the goal of landscape-scale retrievals of snow density, we estimated bulk density and length-scale variability by combining ground-penetrating radar (GPR) two-way travel-time observations and airborne-lidar snow depths collected during the mid-winter NASA SnowEx 2020 campaign at Grand Mesa, Colorado, USA. Key advancements of our approach include an automated layer-picking method that leverages the GPR reflection coherence and the distributed lidar–GPR-retrieved bulk density with machine learning. The root-mean-square error between the distributed estimates and in situ observations is 11 cm for depth, 27 kg m−3 for density, and 46 mm for SWE. The median relative uncertainty in distributed SWE is 13 %. Interactions between wind, terrain, and vegetation display corroborated controls on bulk density that show model and observation agreement. Knowledge of the spatial patterns and predictors of density is critical for the accurate assessment of SWE and essential snow research applications. The spatially continuous snow density and SWE estimated over approximately 16 km2 may serve as necessary calibration and validation for stepping prospective remote-sensing techniques toward broad-scale SWE retrieval.

Comparing floral morphology and inflorescence structure of Lupins argenteus and L. bakeri in sympatry and allopatry - N. Olson (2024)
Differences or similarities in floral morphology can affect the interactions between plants and shared pollinator communities. As such, plant species with similar floral morphology may be competing for pollinators or facilitating pollinator attraction. Thus, pollinators mediate selection on floral morphology. In the Mountain West, two closely related species, Lupinus argenteus and Lupinus bakeri, co-occur, share flower phenology, and have similar floral morphology and inflorescence structures. However, the degree of shared floral morphology and inflorescence structure in areas where both species cooccur compared to areas of where only one, or the other, occurs is unknown. With pollinator mediated selection in mind, this leads to the question, does sympatry predict variation in floral morphology and inflorescence structure of Lupinus bakeri and Lupinus argenteus populations? We took population census data from 5 sites paired across elevation, 3 sympatric populations and 2 allopatric populations, and measure inflorescence structure and floral morphological traits to attempt to answer this question. Based upon our results we found that L. argenteus shows evidence of divergence when in sympatry for the two variables: floral volume and banner to wing gap angle. Which suggests that pollinator sharing between L. argenteus and L. bakeri is competitive. Furthermore, the directionality of this divergence is a trend towards lower floral volume and smaller gap angles, which also suggest that L. argenteus is pollinator filtering. The outcomes of our study, highlights the interactions between floral morphology and pollinator communities, which can lead to potential studies that explore the degree and direction of selection that may, or may not, be present. Furthermore, future studies could use the findings of this project to aid in assessing pollinator communities for each species of subject.

An Unusual Glacial Event in the Comanch Peak Wilderness Area, Larimer County, Colorado - Thomas D. Moeglin; Sanford S. Kaplan (Mountain Geologist, 2024)
Late Pinedale till deposits mapped in various stream valleys in the Comanche Peak Wilderness Area, north of Rocky Mountain National Park, indicate that Browns Creek Valley was glaciated from two directions simultaneously while the middle of the valley remained unglaciated. Till deposits at the upper end of Browns Creek Valley display a well-developed end moraine in a U-shaped valley. Immediately downstream from the end moraine the valley becomes V-shaped, and shows no evidence of glaciation. Another till is encountered in the lower reaches of Browns Creek Valley. This sediment was deposited by a distributary of the main valley glacier moving down Beaver Creek Valley. This subsidiary lobe of the Beaver Creek Valley glacier moved down gradient, but upstream. The tills are texturally distinct from alluvial deposits, but similar to each other. The tills are muddy and sandy boulder gravels, while the alluvial deposits that lie between them are sandy bouldery gravels. Although produced by two separate glaciers, glaciation of the upper and lower parts of Browns Creek Valley appears to have taken place simultaneously.

New Record of Banana Yucca Leafminer, Prodoxus phylloryctus1 in Mesa County, Colorado - Melissa Schreiner (Southwestern Entomologist, 2024)
Una polilla minadora de Yucca baccata, Prodoxus phylloryctus (Wagner y Powell), fue documentada por primera vez en el condado Mesa, Colorado. Prodoxus phylloryctus recientemente recibió el nombre común de minador de hojas de Yucca baccata por parte de la Sociedad Entomológica de América. La primera vez que se detectó el minador de hojas fue durante una interacción con plantas de Y. baccata en el área de Four Corners cerca de Dove Creek, Colorado. En 2022, se documentó el minador en varios sitios en Grand Junction y Fruita, Colorado, donde se encontró interactuando con la yuca ornamental plantada por paisajistas e identificada en la oficina de CSU Extension Tri-River Area-Mesa por el equipo de horticultura.

Model and remote-sensing-guided experimental design and hypothesis generation for monitoring snow-soil–plant interactions - Baptiste Dafflon; Erica R. Siirila-Woodburn; Ian K Breckheimer; Haruko M. Wainwright; Yuxin Wu; Nicola Falco (Frontiers in Water, 2024)
In this study, we develop a machine-learning (ML)-enabled strategy for selecting hillslope-scale ecohydrological monitoring sites within snow-dominated mountainous watersheds, with a particular focus on snow-soil–plant interactions. Data layers rely on spatial data layers from both remote sensing and hydrological model simulations. Specifically, a Landsat-based foresummer drought sensitivity index is used to define the dependency of the annual peak plant productivity on the Palmer drought severity index in the early growing season. Hydrological simulations provide the spatiotemporal dynamics of near-surface soil moisture and snow depth. In this framework, a regression analysis identifies the key hydrological variables relevant to the spatial heterogeneity of drought sensitivity. We then apply unsupervised clustering to these key variables, using the Gaussian mixture model, to group hillslopes into several zones that have divergent relationships regarding soil moisture, snow dynamics, and drought sensitivity. Using the datasets collected in the East River Watershed (Crested Butte, Colorado, United States), results show that drought sensitivity is significantly correlated with model-derived soil moisture and snow-free timing over space and time. The relationship is, however, non-linear, such that the correlation decreases above a threshold elevation and in a heavy snow year due to large snowpacks, lateral flow, and soil storage limitations. Clustering is then able to define the zones that have high or low sensitivity to drought, as well as the mid-elevation regions where sensitivity is associated with the topographic aspect and net potential radiation. In addition, the algorithm identifies the most representative hillslopes with road/trail access within each zone for installing monitoring sites. Our method also aims to significantly increase the use of ML and model-simulation results to guide critical zone and watershed monitoring activities.

Optimizing Field-linked simulations of dry season uptake and monsoon infiltration within an aspen-mixed conifer forest (2024)
Climate models forecast that headwater catchments in the western U.S. will undergo a reduction in snowpack, early season snowmelt, and increases in evapotranspiration. The resulting extended dry season will stress vegetation in mountainous watersheds throughout the Upper Colorado River Basin. We investigate infiltration patterns and root water uptake in response to dry season disturbances within the East River watershed in Colorado. To do this, we collected soil cores, measured matric potential and sap flow, and monitored tree xylem and soil for stable isotopes of water (2H, 18O) in two soil profiles to 90 cm depth (with three Engelmann spruce and three aspen trees instrumented, respectively). Sub-daily stable water isotope dynamics were analyzed between mid-June and late October of WY-22 using a cavity ring-down spectrometer. HYDRUS-1D was calibrated with both field measurements of matric potential and δ2H to simulate the ecosystem response to late summer dry spells and monsoonal rainfall for the 128-day time domain. Simulations show both aspen and spruce trees relying heavily on headwater snowmelt. Water-use analysis reveals a reduction in transpiration during the late summer and early autumn months, particularly in September, the driest month of WY-22. Spruce trees appear more tolerant of dry soil conditions than aspen trees. As a result, it is likely that spruce will outcompete aspen in the future, given forecasted shifts in climate and changes in the timing of snowmelt. This study highlights the benefits of coupling high frequency stable water isotope data and more commonly used matric potential field measurements for parameter optimization in numerical modeling.

The hole truth: why do bumble bees rob flowers more than once? - E. Litchenberg; G. Davidowitz; Rebecca E. Irwin (Plants, 2024)
Primary nectar-robbers feed through holes they make in flowers, often bypassing the plant's reproductive organs in the process. In many robbed plants, multiple holes are made in a single flower. Why a flower should be robbed repeatedly is difficult to understand: a hole signals that a nectar forager has already fed, which would seem likely to predict low rewards. We tested three explanations for this pattern in Corydalis caseana (Fumariaceae), a bumble bee pollinated and robbed plant: (1) multiple holes appear only after all flowers have been robbed once; (2) individual foragers make multiple holes during single visits; and (3) it is more profitable for bees to rob older flowers, even if they have already been robbed. We tested these hypotheses from 2014 to 2016 in a Colorado, USA population using data on robbing rates over time, floral longevity, nectar accumulation in visited and unvisited flowers, and the accumulation of robbing holes across the life of flowers. Multiple holes were already appearing when two-thirds of flowers still lacked a single hole, allowing us to reject the first hypothesis. The second hypothesis cannot offer a full explanation for multiple robbing holes because 35% of additional holes appeared in flowers one or more days after the first hole was made. Repeated sampling of bagged and exposed inflorescences revealed that flowers filled at a constant rate and refilled completely after being drained. Consequently, young flowers are of consistently low value to foragers compared to older flowers even if they had previously been robbed, consistent with the third hypothesis. While further studies are needed, these results offer a simple explanation for the paradoxical clustering of nectar-robbing damage in this and possibly other plant species.

Stream water sourcing from high-elevation snowpack inferred from stable isotopes of water: a novel application of d-excess values - C. Bern; David W. Marchetti; Alexander W. Newman; W. S. Brown; Curtis A. Beutler; Matthias Sprenger; Kenneth Hurst Williams (Hydrology and Earth System Sciences, 2024)
Abstract. About 80 % of the precipitation at the Colorado River's headwaters is snow, and the resulting snowmelt-driven hydrograph is a crucial water source for about 40 million people. Snowmelt from alpine and subalpine snowpack contributes substantially to groundwater recharge and river flow. However, the dynamics of snowmelt progression are not well understood because observations of the high-elevation snowpack are difficult due to challenging access in complex mountainous terrain as well as the cost and labor intensity of currently available methods. We present a novel approach to infer the processes and dynamics of high-elevation snowmelt contributions predicated upon stable hydrogen and oxygen isotope ratios observed in streamflow. We show that deuterium-excess (d-excess) values of stream water could serve as a comparatively cost-effective proxy for a catchment-integrated signal of high-elevation snowmelt contributions to catchment runoff. We sampled stable hydrogen and oxygen isotope ratios of the precipitation, snowpack, and stream water in the East River, a headwater catchment of the Colorado River, and the stream water of larger catchments at sites on the Gunnison River and Colorado River. The d-excess of snowpack increased with elevation; the upper subalpine and alpine snowpack (> 3200 m) had substantially higher d-excess compared to lower elevations (< 3200 m) in the study area. The d-excess values of stream water reflected this because d-excess values increased as the higher-elevation snowpack contributed more to stream water generation later in the snowmelt/runoff season. End-member mixing analyses based on the d-excess data showed that the share of high-elevation snowmelt contributions within the snowmelt hydrograph was on average 44 % and generally increased during melt period progression, up to 70 %. The observed pattern was consistent during 6 years for the East River, and a similar relation was found for the larger catchments on the Gunnison and Colorado rivers. High-elevation snowpack contributions were found to be higher for years with lower snowpack and warmer spring temperatures. Thus, we conclude that the d-excess of stream water is a viable proxy to observe changes in high-elevation snowmelt contributions in catchments at various scales. Inter-catchment comparisons and temporal trends of the d-excess of stream water could therefore serve as a catchment-integrated measure to monitor if mountain systems rely on high-elevation water inputs more during snow drought compared to years of average snowpack depths.

Bee phenological distributions predicted by inferring vital rates - A. Fife; Pearse W.D.; R. Stuart; M. Stemkovski (The American Naturalist, 2024)
AbstractHow bees shift the timing of their seasonal activity (phenology) to track favorable conditions influences the degree to which bee foraging and flowering plant reproduction overlap. While bee phenology is known to shift due to interannual climatic variation and experimental temperature manipulation, the underlying causes of these shifts are poorly understood. Most studies of bee phenology have been phenomenological and have only examined shifts of point estimates, such as first appearance or peak timing. Such cross-sectional measures are convenient for analysis, but foraging activity is distributed across time, and pollination interactions are better described by overlap in phenological abundance curves. Here, we make simultaneous inferences about interannual shifts in bee phenology, emergence and senescence rates, population size, and the effect of floral abundance on observed bee abundance. We do this with a model of transition rates between life stages implemented in a hierarchical Bayesian framework and parameterized with fine-scale abundance time series of the sweat bee Halictus rubicundus at the Rocky Mountain Biological Laboratory in Colorado. We find that H. rubicundus's emergence cueing was highly sensitive to the timing of snowmelt but that emergence rate, senescence rate, and population size did not differ greatly across years. The present approach can be used to glean information about vital rates from other datasets on bee and flower phenology, improving our understanding of pollination interactions.

Pollen chemical and mechanical defences restrict host-plant use by bees - M. Muralidhar; S. Rivest; Jessica R.K. Forrest (Proceedings of the Royal Society B, 2024)
Plants produce an array of chemical and mechanical defences that provide protection against many herbivores and pathogens. Putatively defensive compounds and structures can even occur in floral rewards: for example, the pollen of some plant taxa contains toxic compounds or possesses conspicuous spines. Yet little is known about whether pollen defences restrict host-plant use by bees. In other words, do bees, like other insect herbivores, tolerate the defences of their specific host plants while being harmed by non-host defences? To answer this question, we compared the effects of a chemical defence from Lupinus (Fabaceae) pollen and a putative mechanical defence (pollen spines) from Asteraceae pollen on larval survival of nine bee species in the tribe Osmiini (Megachilidae) varying in their pollen-host use. We found that both types of pollen defences reduce larval survival rate in some bee species. These detrimental effects were, however, mediated by host-plant associations, with bees being more tolerant of the pollen defences of their hosts, relative to the defences of plant taxa exploited by other species. This pattern strongly suggests that bees are adapted to the pollen defences of their hosts, and that host-plant use by bees is constrained by their ability to tolerate such defences.

How does early snowmelt affect pollen deposition on spring wildflowers? - N. Sosa Antunez (2024)
Climate change has led to increasingly warm temperatures, which has caused the earlier snowmelt. This has caused shifts in timing of some plants' growing season and flowering, as well as pollinator emergence. On the other hand, Various pollinators respond to cues such as soil temperature which does not necessarily change at the same rate as snowmelt does under climate change. As pollinators and plants often respond to these different cues for spring emergence, this can lead to a phenological mismatch.This could disrupt relationships between plants and pollinators, potentially leading to changes in pollen deposition. Pollen deposition is critical for plant reproduction. If a flower does not receive the necessary pollen then it is possible the plant will not be able to produce as many seeds. To investigate how early snowmelt affects pollen deposition in wildflowers, I will be studying the species Claytonia lanceolata, Delphinium nuttallianum, and Geum triflorum. These specific species of wildflowers use snowmelt as a cue for their phenology in early spring and are insect pollinated. I will collect stigmas from these species within experimentally-created early snowmelt plots and control plots. The stigmas will then be dyed and plated for pollen grain counting. This research is important because it will allow for a greater understanding of the effect of climate change-induced early snowmelt on plant-pollinator relationships.

Variation in interaction zone size and influence of sex on fitness components of Valeriana edulis - J. A. Davis (2024)
Sex and size allow for many different types of individuals within one species. These individuals can have different needs, which can influence responses to interaction, as well as what interactions take place between species members. We modeled how the sex and size of individuals of Valeriana edulis, a dioecious sub-alpine herb found across the western United States, influences the ways that they interact with neighboring members of their own species. This research could contribute to our ecological understanding of the role of sex and size in intraspecific plant interactions, which could have implications for species conservation under climate change.

Differences in gut microbes across age and sex linked to metabolism and microbial stability in a wild hibernating mammal - M. Pfau; S. Degregori; P. H. Barber; Conner S. Philson; Daniel T. Blumstein (Ecology and Evolution, 2024)
The gut microbiome has a well-documented relationship with host fitness, physiology, and behavior. However, most of what is known comes from captive animals where diets and environments are more homogeneous or controlled. Studies in wild populations that experience dynamic environments and have natural life history variation are less common but are key to understanding the drivers of variation in the gut microbiome. Here we examine a wild population of yellow-bellied marmots (Marmota flaviventer), an obligate winter hibernator, to quantify multivariate associations between host-associated factors (e.g., age, sex, environmental harshness, and social behavior) and gut microbial composition. Across 5 years and 143 individuals, we found that males had a higher relative abundance of microbes associated with mass gain and cellulose digestion, which suggests a metabolic investment in mass gain (such as phylum Firmicutes and family Lachnospiraceae). By contrast, females had higher relative abundances of microbes associated with inflammation and metabolism (from microbial groups such as Tenericutes and Ruminococcus), possibly reflecting the importance of lactation and offspring investment. Post hoc analyses of lactating females showed a negative relationship with the abundance of microbes associated with mass gain but a positive relationship with microbes associated with metabolic energy, suggesting a trade-off between investment in pups and maternal mass gain. Older animals also had reduced Proteobacteria relative abundance, a phylum associated with reduced inflammation. Results demonstrate that sex and age-based traits, not sociality or environmental harshness, are associated with microbe-mediated metabolism and inflammation in a wild, hibernating mammal.

Latest Pleistocene glacial chronology and paleoclimate reconstruction for the East River watershed, Colorado, USA - A. J. Hidy; Brendon Quirk; I. J. Larsen (Quaternary Research, 2024)
Reconstructing Pleistocene glaciation timing and extent is vital for understanding paleoclimate. Whereas late Pleistocene glaciation has been studied extensively in western North American mountain ranges, the glacial history of the western Elk Range in Colorado remains understudied, particularly in the East River watershed, a site of intense scientific focus. Here we use cosmogenic nuclide exposure and depth–profile dating methods to determine the timing of glaciation in the East River watershed. We use glacier modeling to reconstruct paleoglacier extents and quantify past climate conditions. Our findings indicate that the East River glacier retreated from its maximum position approximately 17–18 ka, moving to recessional positions between 13 and 15 ka, before experiencing more substantial retreat to high-elevation cirques around 13 ka. Glacier modeling suggests that the maximum ice extents at 17–18 ka could have been sustained by temperature depressions of approximately −6.5°C compared to modern conditions, assuming consistent precipitation. Additionally, the ice position at 13–15 ka could have been supported by temperature depressions of around −4.0°C. These results offer insights into the deglaciation timeline in the East River watershed and broader western Elk Range as well as paleoclimate conditions during the late Pleistocene, which may aid future research on critical zone evolution in the East River watershed.

The Effects of Early Snowmelt on Drought Stress in Subalpine Plant Species - M. Sinacori (2024)
Subalpine plant species rely on water from snowmelt and monsoons to sustain them through the summer. However, climate change is causing the snow to melt earlier which creates a drought period in June prior to the monsoons and may cause plants to become drought stressed. In order to assess the effect of early snowmelt on subalpine plant drought stress, we conducted a snowmelt timing manipulation using shade cloth to accelerate the timing of snowmelt. To assess the degree of drought stress we measured . stomatal conductance in Linum lewisii and Geum triflorum, chlorophyll fluorescence in Geum triflorum, and the number of flowers on each plant. We found that early snowmelt had no effect on drought stress in L. lewisii and G. triflorum as we saw no differences in stomatal conductance, chlorophyll fluorescence nor stomatal conductance over the flowering period. The lack of drought stress, even with earlier snowmelt, may be due to the large amount of June precipitation which gave the plants adequate water to sustain themselves through the drought period previously seen. This suggests that precipitation has a large impact on subalpine plant species, so it is important to monitor how timing and amount of precipitation affects plants in a changing climate.

Social security: Does social position influence flight initiation distance? - K. Uchida; T. Szulanski; T. Szulanski; Conner S. Philson; Daniel T. Blumstein (Behavioral Ecology, 2024)
A variety of factors can influence an individual’s antipredator behavior including their group size because simply being around conspecifics may reduce predation risk. Recent work has shown that it is not just being around others, but rather the specific social relationships that individuals have with others may also modulate perceptions of risk and explain variation in a variety of antipredator behaviors. We asked whether and how yellow-bellied marmots’ (Marmota flaviventer) position in their social network explains variation in flight initiation distance (FID). We examined the relationship of both direct and indirect measures of sociality and separated models by age and sex classes to isolate the relationships for individuals with different life histories. Following the “social security” hypothesis, we predicted that more socially connected individuals would have a lower FID. We found that the magnitude and direction to which sociality was associated with FID varied based on age and sex. When examining all age- sex cohorts there was a weak effect of strength on FID: individuals in stronger relationships tolerated closer approaches. When examining each cohort independently, we found adult male’s FID was not associated with any social network measure, while female adults fled at greater distances as degree increased. Yearlings of both sexes, however, seemingly benefited from Commented [TS1]: but the directions of the effects are different for both cohorts. AD * closeness increases stronger social relationships, but only when perceived risk was high. These results are consistent FID in FY, but lowers it in MY. is this not important to include in the abstract? with the social security hypothesis; the degree of social connectedness may explain variation in FID in at least some age and sex cohorts.

Thermal infrared shadow-hiding in GOES-R ABI imagery: snow and forest temperature observations from the SnowEx 2020 Grand Mesa field campaign - C. Chris Chickadel; Steven J. Pestana; Jessica D. Lundquist (The Cryosphere, 2024)
Abstract. The high temporal resolution of thermal infrared imagery from the Geostationary Operational Environmental Satellites R-series (GOES-R) presents an opportunity to observe mountain snow and forest temperatures over the full diurnal cycle. However, the off-nadir views of these imagers may impact or bias temperature observations, especially when viewing a surface composed of both snow and forests. We used GOES-16 and -17 thermal infrared brightness temperature observations of a flat snow- and forest-covered study site at Grand Mesa, Colorado, USA, to characterize how forest coverage and view angle impact these observations. These two geostationary satellites provided views of the study area from the southeast (134.1° azimuth, 33.5° elevation) and southwest (221.2° azimuth, 35.9° elevation), respectively. As part of the NASA SnowEx field campaign in February 2020, coincident brightness temperature observations from ground-based and airborne IR sensors were collected to compare with those from the geostationary satellites. Observations over the course of 2 cloud-free days spanned the entire study site. The brightness temperature observations from each dataset were compared to find their relative differences and how those differences may have varied over time and/or as a function of varying forest cover across the study area. GOES-16 and -17 brightness temperatures were found to match the diurnal cycle and temperature range within ∼ 1 h and ± 3 K of ground-based observations. GOES-16 and -17 were both biased warmer than nadir-looking airborne IR and ASTER observations. The warm biases were higher at times when the sun–satellite phase angle was near its daily minimum. The phase angle, the angle between the direction of incoming solar illumination and the direction from which the satellite is viewing, reached daily minimums in the morning for GOES-16 and afternoon for GOES-17. In morning observations, warm biases in GOES-16 brightness temperature were greater for pixels that contained more forest coverage. The observations suggest that a “thermal infrared shadow-hiding” effect may be occurring, where the geostationary satellites are preferentially seeing the warmer sunlit sides of trees at different times of day. These biases are important to understand for applications using GOES-R brightness temperatures or derived land surface temperatures (LSTs) over areas with surface roughness features, such as forests, that could exhibit a thermal infrared shadow-hiding effect.

Declining groundwater storage expected to amplify mountain streamflow reductions in a warmer world - Erica R. Siirila-Woodburn; Charuleka Varadharajan; Richard Niswonger; Craig Ulrich; Kenneth Hurst Williams (Nature Water, 2024)
Abstract Groundwater interactions with mountain streams are often simplified in model projections, potentially leading to inaccurate estimates of streamflow response to climate change. Here, using a high-resolution, integrated hydrological model extending 400 m into the subsurface, we find groundwater an important and stable source of historical streamflow in a mountainous watershed of the Colorado River. In a warmer climate, increased forest water use is predicted to reduce groundwater recharge resulting in groundwater storage loss. Losses are expected to be most severe during dry years and cannot recover to historical levels even during simulated wet periods. Groundwater depletion substantially reduces annual streamflow with intermittent conditions predicted when precipitation is low. Expanding results across the region suggests groundwater declines will be highest in the Colorado Headwater and Gunnison basins. Our research highlights the tight coupling of vegetation and groundwater dynamics and that excluding explicit groundwater response to warming may underestimate future reductions in mountain streamflow.

We’re Not in Texas Anymore: Archaeological Investigations in Historic Dallas, Colorado - Tristan Newberry-Cushman (2024)
This work is the product of an archaeological investigation of the former townsite of Dallas, Colorado. Archival research, drone photography, shovel test pits (STPs), and a test excavation unit were employed to learn more about how the people of Dallas lived, and how they interacted with national systems. Probabilistic and purposive sampling were used to collect data, and both quantitative and qualitative analysis were performed. The goal of this research was to determine which theoretical model best explains how Dallas was connected to national cultural and economic systems.

The Brown Derby No. 1 Pegmatite, Gunnison County, Colorado - Philip M. Persson; Mark Ivan Jacobson (Rocks & Minerals, 2024)

Effects of Dissolved Oxygen & Iron II Concentration Fluxes in Beaver-Impacted Floodplains - W. Hoins (2024)

Nowhere to go but Up: Investigating Bumble Bee population Shifts over Elevational Gradients - R. Scott (2024)
Bumble bees are important pollinators in both the wild and in agriculture; however, several species globally are under threat due to multiple anthropogenic factors. One of these threats is climate change, and many bumble bee species have adapted by moving up in elevation. This has only been observed in specific species, but it does stand to question that with the most recent dramatic global temperature increases, if this will become standard for all species. While this provides the benefit of keeping to a thermal environment necessary for survival and reproduction, competition facilitated by mass migration and isolation could be driving some species further towards extinction. Therefore, it is necessary to understand how species distributions have changed across elevation gradients over the past few years and to understand the mechanisms involved. Results indicate a lack of significance in the data, leading to inconclusive results for the proposed hypotheses. Further experimenting with additional years and low and high elevation sites is necessary to fully evaluate how species are moving.

Social control is associated with increased reproductive skew in a wild mammal - X. Zhang; Adriana A. Maldonado-Chaparro; Conner S. Philson; Daniel T. Blumstein (Biology Letters, 2024)
In group-living species, reproductive variation among individuals of the same sex is widespread. By identifying the mechanisms underlying this reproductive skew, we gain fundamental insights into the evolution and maintenance of sociality. A common mechanism, social control, is typically studied by quantifying dominance, which is one of many attributes of sociality that describes how individuals exert influence on others and is an incomprehensive measure of social control as it accounts only for direct relationships. Here, we use the global reaching centrality (GRC), which quantifies the degree of hierarchy in a social network by accounting for both direct and indirect social relationships. Using a wild, free-living population of adult female yellow-bellied marmots (Marmota flaviventris), we found a positive relationship between the reproductive skew index and GRC: more despotic social groups have higher reproductive skew. The GRC was stronger predictor for skew than traditional measures of social control (i.e. dominance). This allows deeper insights into the diverse ways individuals control other group members' reproduction, a core component in the evolution of sociality. Future studies of skew across taxa may profit by using more comprehensive, network-based measures of social control.

The Impact of Delphinium nuttallianum and Ipomopsis aggregata Phenology on Broad tailed Hummingbird (Selasphorus platycercus) Visitation Patterns - J. Uglialoro (2024)
Biological interactions reliant on synchronized phenology are being thrown into disarray with warming temperatures and an earlier onset of spring. Migrating Broad-tailed Hummingbirds (Selasphorus platycercus) in Gothic, Colorado tend to arrive and breed in alignment with wildflower flowering phenology, fostering important plant-pollinator interactions. Two wildflower species, Delphinium nuttallianum and Ipomopsis aggregata, form a large part of the hummingbirds’ diet and bloom in sync with arrival and breeding milestones. Since both hummingbirds and wildflowers benefit from a synchronized schedule, phenological mismatch would likely decrease hummingbird population persistence through food resource limitation. For this project, we investigated whether weekly changes in Broad-tailed Hummingbird wildflower visitation patterns correspond to changing wildflower phenology in 2022, an earlier-than-average snowmelt year, and 2023, a later-than-average snowmelt year. Due to climate change, years like 2022 with earlier snowmelt are expected to become more common. Using floral phenology transect data and hummingbird visitation data for D. nuttallianum and I. aggregata, we determined that Broad-tailed Hummingbirds adjust their foraging behavior to align with the phenology of their food sources, a behavior that may help prevent the phenological mismatches projected to occur with climate change.

Context dependence of warming induced shifts in montane soil microbial functions - Jennie R McLaren; Aimee T Classen; Sydne Spinella; Nathan J. Sanders (Functional Ecology, 2024)
Abstract High elevation and latitude ecosystems are experiencing high levels of anthropogenic atmospheric warming. Climate warming may directly change soil microbial activity and alter ecosystem carbon dynamics and productivity, but increasing evidence suggests these responses may depend on other biotic factors such as plant community composition and abiotic factors such as moisture. We examined how abiotic (warming) and biotic (presence of dominant plant species) factors interact to affect soil microbial processes. Our experiment deployed the independent and combined treatments of experimental warming and dominant plant species removal in a high and low elevation montane meadows. We analysed multiple soil microbial responses to warming and the presence of a dominant plant at three times throughout the growing season, including soil respiration, microbial metabolic functional diversity, microbial biomass carbon and nitrogen, and extracellular enzyme potential activity. Overall, there were few independent microbial responses to either the warming or the removal treatments. There was a significant interaction between warming and the removal of a dominant plant species, where microbial biomass and the activity of some microbial enzymes were lower in warmed plots where the dominant species was removed relative to control plots. The effect of warming on extracellular enzyme activity was typically observed only at the high‐elevation site. In contrast, we found that effects of warming were consistent across the growing season, despite strong temporal variation in microbial properties. Our results emphasize the need to further consider soil microbial responses to warming under multiple environments, including shifts in both biotic and abiotic factors, to aid in predictions of carbon dynamics under future global change. Read the free Plain Language Summary for this article on the Journal blog.

Coexistence in Burying Beetles: The Niche of Reproductive Temperatures - K. Muse (2024)
Coexistence among species can occur in a variety of ways through niche partitioning. Two major niche components for many organisms are temperature and soil moisture and variation in these may occur with habitat heterogeneity. Near Gothic, Colorado at the Rocky Mountain Biological Laboratory, there are two habitats that pose differences in temperature and soil moisture: aspen forests and montane meadows. Two burying beetles species co-occur in these habitats (Nicrophorus defodiens and Nicrophorus investigator) and overlap significantly in their activity periods, diet, and reproductive behaviors. Temperature and soil moisture impact beetle development, adult flight, burial behaviors, and survival. Larvae are subject to temperature changes, where high temperatures lead to fatality and low temperatures slow development. Adults are subject to high temperatures and desiccation both aboveground and belowground. Aspen forests and montane meadows provide habitat heterogeneity (differing temperatures and soil moistures). I tested the hypothesis that each species has better reproductive success (higher fitness) in different habitats, thus providing a mechanism for their coexistence. I found that N. defodiens had a greater fitness (brood success, larvae number and larvae mass) in the aspen compared to N. investigator, and N. investigator had a higher fitness in the meadow compared to N. defodiens. N. investigator did have similar brood success to N. defodiens in the aspen, but there may be consequences later in their development.

Timing of seasonal events is correlated with social network position in a wild mammal - T. Bastian; C. Bruebach; Billy Barr; Conner S. Philson; Daniel T. Blumstein (Behavioral Ecology and Sociobiology, 2024)
Across animal systems, abiotic environmental features, including timing of seasonal events and weather patterns, affect fitness. An individual’s degree of social integration also has fitness consequences, but we lack an understanding of how abiotic features relate to patterns of individual sociality. A deeper understanding of this relationship could be developed from studying systems where these two links with fitness have already been identified. We explored the relationship between individual social behavior and seasonal timing, seasonal length, and weather patterns. We used social network analysis on a sixteen-year dataset of a wild population of hibernating yellow-bellied marmots (Marmota flaviventer). We fit a series of generalized linear mixed models and found that longer growing seasons before winter hibernation and longer winters were associated with increased individual sociality in the following spring. However, later snowmelt was associated with decreased sociality that spring. We found no relationship between individual sociality and various measures of precipitation and tem- perature. This suggests that seasonal timing and length may be a more important driver of sociality than weather patterns in this system, both as a lag and contemporary effect. Seasonal timing and length may mediate the opportunity or intensity of social interactions. The entwined relationships between the seasonal schedule and weather, and the seemingly contradictory role of winter length and snowmelt, suggests the timing of seasons and its relationship with sociality is complex and further exploration of environment-sociality relationships is required across taxa. Significance statement While the adaptive benefits of social behavior are well studied, less is known about how features of the abiotic environment drive variation in individual social behavior. Given increasing stochasticity in the timing of seasonal events and weather pat- terns, mapping the environment-sociality relationship will provide important insights to the drivers of sociality in the wild. This is particularly salient for species most vulnerable to climate and environmental change, such as seasonal hibernators, like yellow-bellied marmots (Marmota flaviventer). We found that features of seasonal duration were positively associated with increased sociality, whereas the timing of seasonal onset was negatively associated. This work provides empirical evidence towards an important gap in the behavioral ecology literature.

Scaling Landscape Fire History: Wildfires Not Historically Frequent in the Main Population of Threatened Gunnison Sage-Grouse (Fire, 2024)
The main population of ~5000 threatened Gunnison sage-grouse (GUSG; Centrocercus minimus) in Colorado depends on sagebrush plants that are killed by wildfires, with recovery taking decades, so frequent fire is a threat, but did it occur historically? Early land surveys showed that the historical (preindustrial) fire rotation (FR), the expected period to burn area equal to a focal land area, was 90–143 years in GUSG ranges, which is not classed as frequent fire (≤25 years). However, recent research, based on fire scars on trees at ten sites near sagebrush, suggested some frequent fire historically in the main population. That study was not spatial, essential to estimate FR, so spatial data were created in GIS with land-survey reconstructions, survey dates, fire-scar sites, mapped sagebrush, and Thiessen polygons around sites. The previous study assumed fires that burned 2+ sites likely burned across sagebrush. Historical FRs were calculated several ways over a common period. A recovery estimate of FR was 90–135 years, a land-survey estimate was 82–131 years, and three spatial scar-based estimates were 93–107 years, showing agreement. However, the comparison found that only 8.8% of the land-survey fire area was detected at fire-scar sites. Detailed analysis showed that 10 fire-scar sites were insufficient to detect historical fire sizes and distributions across the large 168,753 ha sagebrush area. Adequate fire reconstruction could require ~45–60 fire-scar sites, making it feasible to study only ~30,000 ha of sagebrush. Using the two remaining methods, which cross-validate, showed frequent fire did not occur historically in the study area, as historical FRs were 82–135 years.

Biofluorescence as a Mechanism of Sexual Selection in Ambystoma mavortium nebulosum - S. von der Ohe (2024)
Biofluorescence, the re-emission of absorbed light at lower energy wavelengths, has been widely documented in marine organisms and recently observed in amphibians. This phenomenon, particularly in amphibians such as frogs, salamanders, and newts, suggests potential roles in ecological interactions, including communication, mate selection, and predator avoidance. Despite advancements, the functional role of biofluorescence, especially regarding sexual selection, remains unclear. This study investigated the role of biofluorescence in sexual selection among Arizona Tiger Salamanders (Ambystoma tigrinum nebulosum), focusing on its behavioral functions and implications for conservation at the Mexican Cut in Colorado over the summer of 2024. Using a series of controlled experiments, we examined salamander preferences for different colored light and biofluorescent versus non-biofluorescent potential mates under blue light exposure. Results from glow stick and blue light control experiments indicate no significant sex-based differences in trap choices, but a general attraction to green and blue light was observed. In biofluorescence choice experiments, females showed a significant preference against biofluorescent males, whereas males exhibited no preference for biofluorescent females. These findings suggest that while blue light is a crucial visual cue, biofluorescence may not play a significant role in sexual selection in this species. Understanding the role of biofluorescence in amphibians could enhance non-invasive monitoring techniques and conservation strategies, particularly given the global decline in amphibian populations. This research provides new insights into amphibian behavior and ecology, contributing to improved conservation methods and a deeper understanding of biofluorescence's ecological and evolutionary significance.

Polyphenism predicts actuarial senescence and lifespan in tiger salamanders - H. Cayuela; B. Monod-Broca; A. C. R. Lackey; V. Ronget; Howard Whiteman (Journal of Animal Ecology, 2024)
Actuarial senescence (called 'senescence' hereafter) often shows broad variation at the intraspecific level. Phenotypic plasticity likely plays a central role in among-individual heterogeneity in senescence rate (i.e. the rate of increase in mortality with age), although our knowledge on this subject is still very fragmentary. Polyphenism-the unique sub-type of phenotypic plasticity where several discrete phenotypes are produced by the same genotype-may provide excellent study systems to investigate if and how plasticity affects the rate of senescence in nature. In this study, we investigated whether facultative paedomorphosis influences the rate of senescence in a salamander, Ambystoma mavortium nebulosum. Facultative paedomorphosis, a unique form of polyphenism found in dozens of urodele species worldwide, leads to the production of two discrete, environmentally induced phenotypes: metamorphic and paedomorphic individuals. We leveraged an extensive set of capture-recapture data (8948 individuals, 24 years of monitoring) that were analysed using multistate capture-recapture models and Bayesian age-dependent survival models. Multistate models revealed that paedomorphosis was the most common developmental pathway used by salamanders in our study system. Bayesian age-dependent survival models then showed that paedomorphs have accelerated senescence in both sexes and shorter adult lifespan (in females only) compared to metamorphs. In paedomorphs, senescence rate and adult lifespan also varied among ponds and individuals. Females with good body condition and high lifetime reproductive success had slower senescence and longer lifespan. Late-breeding females also lived longer but showed a senescence rate similar to that of early-breeding females. Moreover, males with good condition had longer lifespan than males with poor body condition, although they had similar senescence rates. In addition, late-breeding males lived longer but, unexpectedly, had higher senescence than early-breeding males. Overall, our work provides one of the few empirical cases suggesting that environmentally cued polyphenism could affect the senescence of a vertebrate in nature, thus providing insights on the ecological and evolutionary consequences of developmental plasticity on ageing.

COLORADO RIVER BASIN UPDATE - Lawrence J. MacDonnell (SSRN Electronic Journal, 2024)

Ecosystem-size relationships of river populations and communities - J. D. Tonkin; C. M. Febria; A. R. McIntosh; H. S. Greig; H. J. Warburton (Trends in Ecology & Evolution, 2024)
Knowledge of ecosystem-size influences on river populations and communities is integral to the balancing of human and environmental needs for water. The multiple dimensions of dendritic river networks complicate understanding of ecosystem-size influences, but could be resolved by the development of scaling relationships. We highlight the importance of physical constraints limiting predator body sizes, movements, and population sizes in small rivers, and where river contraction limits space or creates stressful conditions affecting community stability and food webs. Investigations of the scaling and contingency of these processes will be insightful because of the underlying generality and scale independence of such relationships. Doing so will also pinpoint damaging water-management practices and identify which aspects of river size can be most usefully manipulated in river restoration.

Costly calling: Marmots who alarm call at higher rates are less likely to survive the summer and live shorter lives - J. Uy; K. A. Adler; Daniel T. Blumstein (Current Zoology, 2024)
Emitting alarm calls may be costly, but few studies have asked whether calling increases a caller's risk of predation and survival. Since observing animals calling and being killed is relatively rare, we capitalized on over 24,000 h of observations of marmot colonies and asked whether variation in the rate that yellow-bellied marmots (Marmota flaviventer) alarm called was associated with the probability of summer mortality, a proxy for predation. Using a generalized mixed model that controlled for factors that influenced the likelihood of survival, we found that marmots who called at higher rates were substantially more likely to die over the summer. Because virtually all summer mortality is due to predation, these results suggest that calling is indeed costly for marmots. Additionally, the results from a Cox survival analysis showed that marmots that called more lived significantly shorter lives. Prior studies have shown that marmots reduce the risk by emitting calls only when close to their burrows, but this newly quantified survival cost suggests a constraint on eliminating risks. Quantifying the cost of alarm calling using a similar approach in other systems will help us better understand its true costs, which is an essential value for theoretical models of calling and social behavior.

Recent Upper Colorado River Streamflow Declines Driven by Loss of Spring Precipitation - Jessica D. Lundquist (Geophysical Research Letters, 2024)
Abstract Colorado River streamflow has decreased 19% since 2000. Spring (March‐April‐May) weather strongly influences Upper Colorado River streamflow because it controls not only water input but also when snow melts and how much energy is available for evaporation when soils are wettest. Since 2000, spring precipitation decreased by 14% on average across 26 unregulated headwater basins, but this decrease did not fully account for the reduced streamflow. In drier springs, increases in energy from reduced cloud cover, and lowered surface albedo from earlier snow disappearance, coincided with potential evapotranspiration (PET) increases of up to 10%. Combining spring precipitation decreases with PET increases accounted for 67% of the variance in post‐2000 streamflow deficits. Streamflow deficits were most substantial in lower elevation basins (<2,950 m), where snowmelt occurred earliest, and precipitation declines were largest. Refining seasonal spring precipitation forecasts is imperative for future water availability predictions in this snow‐dominated water resource region.

METHODS: Validating an immunoassay to measure fecal glucocorticoid metabolites in yellow-bellied marmots - E. Press; S. Rhone; H. B. Taha; X. Ortiz Ross; Daniel T. Blumstein (Comparative Biochem and Phys Part A: Mol and Int, 2024)
Quantifying physiological stress in wild animals is essential for understanding their health, reproductive success, and survival in a variable environment. The yellow-bellied marmot (Marmota flaviventer) study at the Rocky Mountain Biological Laboratory near Crested Butte, Colorado, USA is the world's second longest study of free-living mammals. Historically, we used a validated corticosterone radioimmunoassay (RIA) to measure fecal glucocorticoid metabolites (FGMs) as a proxy for physiological stress. However, the costs and risks associated with working with radioisotopes drove us to consider a more sustainable method. Here we evaluate the suitability of two competitive corticosterone enzyme-linked assays (EIA), one from Cayman Chemical Company (CCC) and one from Arbor Assays (AA), to measure marmot FGMs via its cross-reaction. The findings revealed that the AA EIA better matched the RIA in terms of accuracy across high and low FGM concentrations, had superior assay parameters, showed the highest correlations with RIA results and effectively captured the annual variations in FGM concentrations, thus demonstrating its reliability for use in longitudinal studies. We further analytically validated the AA EIA for FGMs and confirmed its efficacy and lack of matrix effects, thus establishing its suitability for ongoing and future studies of FGMs in marmots. The transition to the AA EIA from the RIA ensures continued data integrity while enhancing safety and environmental sustainability.

A habitat‐centered framework for wildlife climate change vulnerability assessments: Application to Gunnison sage‐grouse - Nathan D Van Van Schmidt (Ecosphere, 2024)
AbstractThe persistence of threatened wildlife species depends on successful conservation and restoration of habitats, but climate change and other stressors make these tasks increasingly challenging. Applying climate change vulnerability analyses to contemporary wildlife management can be difficult because most analyses predict direct effects of future climate on wildlife species at broad geographic scales, rather than assessing their habitats at local scales (<1 km) that correspond to site‐specific habitat management actions. We present a framework that synthesizes vegetation‐focused vulnerability assessments to assess multiple effects on wildlife species' diverse habitat needs, providing a scenario‐driven climate vulnerability assessment that maps differences in vulnerability of populations within a species' range. Our flexible habitat‐centered synthesis approach leverages available spatial datasets describing projected exposure to vegetation changes due to climate change and other potentially synergistic stressors, reclassifies and weights them based on available estimates of species' sensitivity to these changes, and recombines them to create <1‐km resolution maps of overall species vulnerability and threat‐specific habitat vulnerability. To demonstrate its potential to guide decision‐making, we applied this approach to the Gunnison sage‐grouse (Centrocercus minimus), a federally threatened habitat specialist that depends on sagebrush and mesic habitats that are imperiled by climate change. We mapped six threats forecasted out to the year 2070: direct effects of climate on (1) sagebrush cover loss and (2) mesic habitat drying, indirect changes in invasion risk from (3) pinyon–juniper conifers and (4) annual grasses, and potentially synergistic risk of (5) development and (6) wildfire. We then assessed species vulnerability for each of the eight extant populations under three climate scenarios: Optimistic, Continuation, and Pessimistic. We found that the extent of cumulative species vulnerability due to multiple habitat changes was far greater than the extent of any single habitat vulnerability. Over 75% of critical habitats were at risk under the Pessimistic scenario, and nearly two thirds of habitats were at high risk for three or more threats. Invasive species were the most widespread threat, highlighting the importance of indirect effects of climate change. We illustrate how our approach can be applied to the existing management planning strategies to better prioritize conservation of habitats for the persistence of threatened species.

Patterns of genetic variation and local adaptation of a native herbivore to a lethal invasive plant - Rachel A Steward; Nitin Ravikanthachari; Carol L. Boggs (Molecular Ecology, 2024)
Understanding the evolutionary processes that influence fitness is critical to pre- dicting species' responses to selection. Interactions among evolutionary processes including gene flow, drift and the strength of selection can lead to either local adap- tation or maladaptation, especially in heterogenous landscapes. Populations experi- encing novel environments or resources are ideal for understanding the mechanisms underlying adaptation or maladaptation, specifically in locally co-evolved interac- tions. We used the interaction between a native herbivore that oviposits on a patchily distributed introduced plant that in turn causes significant mortality to the larvae to test for signatures of local adaptation in areas where the two co-occurred. We used whole-genome sequencing to explore population structure, patterns of gene flow and signatures of local adaptation. We found signatures of local adaptation in response to the introduced plant in the absence of strong population structure with no genetic differentiation and low genetic variation. Additionally, we found localized allele fre- quency differences within a single population between habitats with and without the lethal plant, highlighting the effects of strong selection. Finally, we identified that se- lection was acting on larval ability to feed on the plant rather than on females’ ability to avoid oviposition, thus uncovering the specific ontogenetic target of selection. Our work highlights the potential for adaptation to occur in a fine-grained landscape in the presence of gene flow and low genetic variation.

Effects of water availability on expression of vegetative traits in Ipomopsis across space and time - L. Emanuel (2024)
In subalpine ecosystems, climate change has contributed to an earlier snowmelt as a result of warmer temperatures in the winter and spring. This shift may act to limit water availability for plant communities by prolonging the period between initial snowmelt and late-season monsoon rains, placing these systems at risk of more frequent and severe drought. The genus Ipomopsis—a perennial subalpine plant—has been the subject of a long-term study at RMBL examining the effects of climate change on phenotype. Previous research has identified several vegetative traits in the genus whose expression can vary based on environmental factors including snowmelt date and soil moisture. This project aims to examine how water availability, specifically soil moisture, affects the expression of vegetative traits in Ipomopsis using both spatial (2024 data) and long-term temporal comparisons. Four traits—trichome density, specific leaf area (SLA), leaf volumetric water content (VWC), and photosynthetic water use efficiency (WUE)—were measured, along with soil moisture, from plants in three populations. Additionally, historical data were analyzed to compare vegetative traits and snowmelt date over 15 years. Relationships between trait expression and water availability were found to be stronger in historical comparisons than in spatial comparisons, likely as a result of abnormally wet conditions during June of 2024. Higher soil moisture, however, predicted higher leaf VWC in this year’s data, and years with later snowmelt date had higher SLA. Trichome density did not change significantly with snowmelt date. Finally, WUE was influenced by an interaction between site and snowmelt date. 1

Estimating Local Abundance of Bombus Queens in Meadows of Rocky Mountains, Colorado, USA - M. Shaffer (2024)

Potential for Events Similar to the Deadly West Salt Creek Landslide, Grand Mesa Area, Colorado - Bennett Emmons; Emily Sparks; Omid Arabnia; Paul Michael Santi (Environmental & Engineering Geoscience, 2024)
ABSTRACT The deadly West Salt Creek Landslide of 2014, one of the largest landslides to occur in the United States in historical time, was surprising in its suddenness and length of runout. Its source area, the edge of Grand Mesa in western Colorado, was potentially the source of other similar landslides in the past, based on previous mapping in the region. The purpose of this research was to evaluate the potential for similar events by detailed mapping of several canyons flanking West Salt Creek, using aerial imagery and age-dating techniques not available to previous mappers. We conclude that, while the West Salt Creek Landslide has the potential to reactivate in a similar manner to the 2014 movement, the potential for a similar event in the flanking canyons is low. Mapping and semi-quantitative geomorphic methods suggest that the deposits present in several canyons on either side of West Salt Creek are glacial or stream deposits, with one canyon containing debris-flow deposits. Our interpretations are based on the morphology of deposits in the canyons, the presence of specific landform features, measurements of mobility index and longitudinal profiles, and comparison with regional analogs. Furthermore, other mass movements in the region that are of similar magnitude had either slower movement or much shorter runout. The large block at the head of West Salt Creek and the earlier block that shattered and mobilized in 2014 are also unique features locally, distinguishing this setting from others, but also indicating the potential for a future similar event.

Hydrological control of rock carbon fluxes from shale weathering - Amanda Henderson; Anh Phuong Tran; Markus Bill; Tetsu Tokunaga; Jiamin Wan; Alexander W. Newman; Wenming Dong; W. S. Brown; Curtis A. Beutler; Kenneth Hurst Williams (Nature Water, 2024)
Shale bedrocks hold Earth’s largest carbon inventory. Although water is recognized for cycling elements through terrestrial environments, understanding how hydrology controls ancient rock carbon (Crock) release is limited. Here we measured depth- and season-dependent subsurface water fluxes and pore-water and pore-gas geochemistry (including radiocarbon) over five vastly different water years along a hillslope. The data reveal that the maximum depth of annual water table oscillations determines the weathering depth. Seasonally varying subsurface water fluxes determine the export forms and rates of weathered Crock. Eighty percent of released Crock is emitted as CO2 to the atmosphere primarily during warmer and lower water table seasons and 20% of released Crock as bicarbonate exports mostly during months of snowmelt to the hydrosphere. Thus, the rates and forms of Crock weathering and export are clearly controlled by climate via hydrologic regulation of oxygen availability and subsurface flow. The approaches developed here can be applied to other environments. This study shows that climate-driven hydrology primarily controls subsurface rock carbon weathering, with the groundwater table regulating the weathering depth and subsurface water fluxes determining the transported forms and rates of carbon released from rocks, based on measurements in the East River watershed, Rocky Mountains, United States.

The effects of advanced plant phenology on herbivory and plant demography (2024)

Does current weather or seasonality influence antipredator vigilance in a hibernating mammal? - K. Bobb (2024)

Decomposing an elevational gradient in predation by insectivorous birds - Luis Abdala-Roberts; Kailen A. Mooney; C. Vazquez-Gonzalez (Ecosphere, 2024)
Abstract Insectivorous birds have ecologically important effects on prey abundance, behavior, and evolution, and through top‐down control, birds indirectly reduce herbivory and promote plant growth. While several studies sought to characterize biogeographic patterns in top‐down control by birds, variation in bird predation along elevational gradients is not well characterized in terms of both its commonness and the mechanisms underlying such variation. Here, we characterized variation in bird predation along a 700‐m montane elevation gradient using artificial clay caterpillars, assessing the roles of variation in aridity, other elevational effects not associated with aridity (e.g., most notably growing season length), and bird abundance and diversity. Multivariate models revealed increasing attack rates with aridity (when controlling for the effects of elevation) and elevation (when controlling for aridity). Because aridity declines with elevation, elevational patterns were not detectable in a univariate analysis. Bird abundance (but not diversity) decreased with elevation (but not aridity) and did not provide an explanation for our results, suggesting that the underlying mechanisms were behaviorally based. We speculate that the declining abundance of insect prey with elevation and aridity leads to increased bird foraging efforts and thus the likelihood of attacking clay caterpillars. If widespread, these dynamics have important consequences for both the interpretation of predation bioassays generally and our understanding of the multivariate drivers of variation in top‐down control by predators and predation risks experienced by prey.

Consequences of nuisance algal blooms of Didymosphenia geminata on invertebrate communities in Rocky Mountain streams - M. Brogan; B. L. Peckarsky; J. Resasco (Freshwater Science, 2024)
As climate change accelerates, low summer stream flows are becoming increasingly common in the Colorado Rocky Mountains, USA. The diatom Didymosphenia geminata (Lyngb.) M. Schmidt, typically observed under low-flow and low-P conditions, produces nuisance growth—persistent and extensive proliferation, covering the bottoms of streams in thick algal mats. Nuisance blooms of this diatom physically alter the benthic environment and thereby affect freshwater invertebrates directly and indirectly by altering stream food webs. We compared 9 y of survey data (2013–2021) of D. geminata proliferation with the composition of the macroinvertebrate communities at 8 stream sites near the Rocky Mountain Biological Laboratory in western Colorado. We counted and identified samples of benthic macroinvertebrates and used a glass-bottomed viewing box to estimate D. geminata biovolume at 2 scales: macrohabitat conditions (site level: 2013–2021) and microhabitat conditions (sample level: 2020–2021). At both scales, increases in D. geminata proliferation were associated with shifts in macroinvertebrate community composition that could be explained by altered abundances of focal taxa, specifically declines in Heptageniidae (Ephemeroptera) and increases in Chironomidae (Diptera). Abundances of Baetidae (Ephemeroptera) were unaffected by increased D. geminata biovolume. These changes indicate degradation of stream habitat for some sensitive groups of macroinvertebrates, which may affect higher trophic levels, such as trout, in these mountain stream ecosystems. As climate change trends toward lower summer streamflow, understanding the effects of proliferation of this ecosystem engineer is key to predicting the impact of climate change on stream food webs.

Changes in insect population dynamics due to climate change - Carol L. Boggs (Effects of Climate Change on Insects: Physiological, Evolutionary, and Ecological Responses, 2024)
Abstract Climate change can modify the population dynamics of insects. In this instance, “climate” encompasses temperature and precipitation patterns, including dry season or snow cover duration and timing. Also included are changes in both climate means and variances. Insect declines in response to climate change are real but population dynamics are heterogeneous across space and taxa. Both rates of climate change and the location of a population within its climate envelope affect the outcome. Our understanding is currently limited by five factors. First, insect monitoring studies cover a narrow geographic range. Second, other anthropogenic changes, such as land-use change, jointly affect the results of climate change on insect dynamics. Third, species interactions may be affected by climate change, with resulting indirect effects on insect dynamics. Fourth, our understanding of the underlying physiological and fitness response to weather extremes is still limited for insects. Fifth, we have an insufficient understanding of the dynamics of changes in vital rates, which control population dynamics, in response to climate change. This chapter examines these factors, with an emphasis on temperate and arctic species.

Forest composition and structural controls on canopy snow interception in a Colorado watershed - Curtis A. Beutler (2024)
Globally and across the Western United States shifting climate regimes have the ability to propagate change throughout ecosystems and affect their associated hydrologic functions. In mountain regions, which serve as “water towers” for much of humanity, the complex interactions between vegetation and water are especially vulnerable to climate change as they are subject to both ecological and hydrological disturbances. Forests exhibit major controls on the hydrology of mountain systems, of which a primary mechanism is the interception of falling snow in forest canopies which can result in up to 50% of intercepted snow being lost back to the atmosphere through sublimation. Despite being an important driver of forest-snow interactions, scientific inquiry on canopy snow interception has been limited to small spatial scales and limited observations due to the difficult nature of measuring snow in forest canopies. We used Terrestrial Laser Scanning (TLS) to quantify interception rates and interrogate how tree species, forest structure, and weather conditions influence canopy snow interception potential in a high elevation Colorado watershed. Our results represent a step forward in expanding the spatial scale of canopy snow observations and elucidating the differences in interception rates across different tree species, forest compositions, and structures. We compared deciduous tree stands comprised of Quaking Aspen against 3 prevalent coniferous tree species at this altitude (Lodgepole Pine, Engelmann Spruce, and Subalpine Fir) and found that on average conifer forests intercepted an order of magnitude greater snow volume. Analysis of a supplementary dataset on snowpack depth revealed that aspen stands had a 22% greater snow depth on average, despite wide ranges

Cumulative adversity and survival in the wild - X. Ortiz Ross; Daniel T. Blumstein (Ecology Letters, 2024)
Protecting populations contending with co-occurring stressors requires a better understanding of how multiple early-life stressors affect the fitness of natural systems. However, the complexity of such research has limited its advancement and prevented us from answering new questions. In human studies, cumulative risk models predict adult health risk based on early adversity exposure. We apply a similar framework in wild yellow-bellied marmots (Marmota flaviventer). We tested cumulative adversity indices (CAIs) across different adversity types and time windows. All CAIs were associated with decreased pup survival and were well supported. Moderate and acute, but not standardized CAIs were associated with decreased lifespan, supporting the cumulative stress hypothesis and the endurance of early adversity. Multivariate models showed that differences in lifespan were driven by weaning date, precipitation, and maternal loss, but they performed poorly compared with CAI models. We highlight the development, utility, and insights of CAI approaches for ecology and conservation.

A new Late Cretaceous metatherian from the Williams Fork Formation, Colorado - Joshua Cohen; Andrew B. Heckert; Jaelyn Eberle (PLOS ONE, 2024)
Heleocola piceanus, a new, relatively large metatherian from Upper Cretaceous (‘Edmontonian’) strata of the Williams Fork Formation in northwestern Colorado is described, based on a recently discovered jaw fragment (MWC 9744), in addition to three isolated teeth initially referred by other studies to Aquiladelphis incus and Glasbius piceanus. Although sharing several morphologic characters with the Lancian genus Glasbius, H. piceanus lower molars are considerably larger than those of Glasbius and differ from the latter in lacking a buccal cingulid, possessing carnassiform notches on the cristid obliqua and entocristid, and bearing an entoconulid on m3. To examine the relationship of Heleocola piceanus to other metatherians, H. piceanus was scored into a previously existing taxon-character matrix. Our phylogenetic analysis recovers H. piceanus as the sister taxon to Glasbius, which is consistent with our morphologic comparisons. H. piceanus represents the oldest member of the Glasbiidae. A regression equation for predicting body mass of dentally conservative metatherians that utilizes the length of m1 estimates the mass of H. piceanus at 855–1170 g, which is comparable in mass to today’s muskrat (Ondatra zibethicus) and large relative to other Late Cretaceous pediomyoids. Based upon its molar morphology, specifically the low inflated cusps, low height differential between the trigonid and talonid, and near-bunodont morphology, H. piceanus is interpreted as an omnivore with a plant-dominated diet.

The Impact of Environmental Factors on Arizona Tiger Salamander Larval Growth - J. Bornyasz (2023)
Amphibians have been hit particularly hard by the recent era of biodiversity loss (Collins 2009). Understanding the factors that influence their growth and development can help us understand their global decline as well as the dynamics of populations in widely different habitats. Growth rates have been observed to vary dramatically between low elevation (6000 ft) and high elevation (12,000 ft) habitats (Whiteman and Wissinger 2005). Larval growth rates have important implications for life fitness and reproductive success, influencing the morphology of sexually mature salamanders and the size and age at first reproduction (Whiteman 1994; Semlitsch et al.1988). Larval growth rates and physical characteristics are impacted by environmental factors like temperature, elevation, and pond hydroperiod (Wissenger et al. 2010; Semlitsch et al. 1988). This study will investigate the influence of environmental conditions on larval growth rates in Arizona tiger salamanders. Salamander larvae as well as sexually mature paedomorphic and metamorphic salamanders will be collected and measured from sites ranging in elevation. This data will be compared against multiple environmental variables such as elevation, water chemistry, solar input, and pond hydroperiod. Statistical analysis will reveal which variables or combination of variables have the greatest influence on larval growth rates and ultimately inform our understanding of salamander population dynamics between vastly different sampling sites.

Do pollinator and plant diversity vary with microclimate heterogeneity? - E. Warmerdam (2023)
Montane landscapes are topographically complex and contain a biodiverse community of flora and pollinators. As with many other ecosystems, these subalpine and alpine landscapes are changing with the climate, altering the way these ecosystems regulate. As climates become warmer and drier, microclimates offer pockets of coolness that offset the changing seasons. Microclimates allow for snowpack to last longer in some areas and melt out quicker and others hedging the bets for the survival of plant species. Studying this will give us data as to how plants are adapting to climate change. In order to understand how plant-pollinator diversity is being impacted by the climate we did look at floral community composition and pollinator diversity variation between high and low heterogeneity plots. From this data we hope to see that diversity will increase with higher microclimates. In order to test this we will be sampling for pollinators across different transects as well as doing floral phenology counts. Methods of assessing species richness of pollinators will be the same as they are in the Irwin datasets taking into account their identity and what flowers they visit. From this we can see how pollinator diversity is associated with plants diversity. We learned in our data collection that floral diversity is partial to high heterogeneity transects and that pollinators are responding to floral abundance, not plant diversity. In our efforts to preserve different organisms under climate change, floral abundance is an important metric to keep in mind. Protocols for this data collection came from metadata files for David Inouye’s database on flowering phenology and methods developed by Dr. Becky Irwin for Phenology of subalpine bee and plant communities.

Perception of experiential value in luxury hotel settings: The case of experiential programming and impact on consumers (2023)
A luxury shift has occurred and been reflected in the way consumers now define luxury.

Demographic consequences of changes in environmental periodicity - Kenneth B. Armitage; Eva Conquet; Maria Paniw; Julien G. A. Martin; Daniel T. Blumstein (Ecology, 2023)
The fate of natural populations is mediated by complex interactions among vital rates, which can vary within and among years. Although the effects of random, among-year variation in vital rates have been studied extensively, relatively little is known about how periodic, nonrandom variation in vital rates affects populations. This knowledge gap is potentially alarming as global environmental change is projected to alter common periodic variations, such as seasonality. We investigated the effects of changes in vital-rate periodicity on populations of three species representing different forms of adaptation to periodic environments: the yellow-bellied marmot (Marmota flaviventer), adapted to strong seasonality in snowfall; the meerkat (Suricata suricatta), adapted to inter-annual stochasticity as well as seasonal patterns in rainfall; and the dewy pine (Drosophyllum lusitanicum), adapted to fire regimes and periodic post-fire habitat succession. To assess how changes in periodicity affect population growth, we parameterized periodic matrix population models and projected population dynamics under different scenarios of perturbations in the strength of vital-rate periodicity. We assessed the effects of such perturbations on various metrics describing population dynamics, including the stochastic growth rate, log λS . Overall, perturbing the strength of periodicity had strong effects on population dynamics in all three study species. For the marmots, log λS decreased with increased seasonal differences in adult survival. For the meerkats, density dependence buffered the effects of perturbations of periodicity on log λS . Finally, dewy pines were negatively affected by changes in natural post-fire succession under stochastic or periodic fire regimes with fires occurring every 30 years, but were buffered by density dependence from such changes under presumed more frequent fires or large-scale disturbances. We show that changes in the strength of vital-rate periodicity can have diverse but strong effects on population dynamics across different life histories. Populations buffered from inter-annual vital-rate variation can be affected substantially by changes in environmentally driven vital-rate periodic patterns; however, the effects of such changes can be masked in analyses focusing on inter-annual variation. As most ecosystems are affected by periodic variations in the environment such as seasonality, assessing their contributions to population viability for future global-change research is crucial.

Silviculture - Kristen M. Waring; Ethan Bucholz (2023)
Abstract Silviculture is the art and science of managing forest stands to meet landowner goals and objectives; traditional examples of goals and objectives include managing for timber production, improved wildlife habitat, fuels reduction, and maintenance or improvement of forest health.

Leveraging groundwater dynamics to improve predictions of summer low-flow discharges - A. Harpold; H. R. Barnard; Mark S. Raleigh; Langlang Li; Wenming Dong; Kenneth Hurst Williams (Water Resources Research, 2023)
Abstract Summer streamflow predictions are critical for managing water resources; however, warming‐induced shifts from snow to rain regimes impact low‐flow predictive models. Additionally, reductions in snowpack drive earlier peak flows and lower summer flows across the western United States increasing reliance on groundwater for maintaining summer streamflow. However, it remains poorly understood how groundwater contributions vary interannually. We quantify recession limb groundwater (RLGW), defined as the proportional groundwater contribution to the stream during the period between peak stream flow and low flow, to predict summer low flows across three diverse western US watersheds. We ask (a) how do snow and rain dynamics influence interannual variations of RLGW contributions and summer low flows?; (b) which watershed attributes impact the effectiveness of RLGW as a predictor of summer low flows? Linear models reveal that RLGW is a strong predictor of low flows across all sites and drastically improves low‐flow prediction compared to snow metrics at a rain‐dominated site. Results suggest that strength of RLGW control on summer low flows may be mediated by subsurface storage. Subsurface storage can be divided into dynamic (i.e., variability saturated) and deep (i.e., permanently saturated) components, and we hypothesize that interannual variability in dynamic storage contribution to streamflow drives RLGW variability. In systems with a higher proportion of dynamic storage, RLGW is a better predictor of summer low flow because the stream is more responsive to dynamic storage contributions compared to deep‐storage‐dominated systems. Overall, including RLGW improved low‐flow prediction across diverse watersheds.

The dispersal of microbes among and within flowers by butterflies - M. Olson; M. Blackwell; Nitin Ravikanthachari; Carol L. Boggs (Ecological Entomology, 2023)
Abstract Floral microbes, including bacteria and fungi, alter nectar quality, thus changing pollinator visitation. Conversely, pollinator visitation can change the floral microbial community. Most studies on dispersal of floral microbes have focused on bees, ants or hummingbirds, yet Lepidoptera are important pollinators. We asked (a) where are microbes present on the butterfly body, (b) do butterflies transfer microbes while foraging, and (c) how does butterfly foraging affect microbial abundance on different floret structures. The tarsi and proboscis had significantly more microbes than the thorax in wild‐caught Glaucopsyche lygdamus (Lepidoptera: Lycaenidae) and Speyeria mormonia (Lepidoptera: Nymphalidae). Glaucopsyche lygdamus , a smaller‐bodied species, had fewer microbes than S. mormonia. As a marker for microbes, we used a bacterium ( Rhodococcus fascians, near NCBI Y11196) isolated from a S. mormonia that was foraging for nectar, and examined its dispersal by G. lygdamus and S. mormonia visiting florets of Pyrrocoma crocea (Asteraceae). Microbial dispersal among florets correlated positively with bacterial abundance in the donor floret. Dispersal also depended on butterfly species, age, and bacterial load carried by the butterfly. Recipient florets had less bacteria than donor florets. The nectaries had more bacteria than the anthers or the stigmas, while anthers and stigmas did not differ from each other. There was no differential transmission among floral organs. Lepidoptera thus act as vectors of floral microbes. Including Lepidoptera is thus crucial to an understanding of plant–pollinator–microbe interactions. Future studies should consider the role of vectored microbes in lepidopteran ecology and fitness.

Climate data from the Rocky Mountain Biological Laboratory (1975–2022) - R. M. Prather; barr b; Rebecca M. Dalton; N. C. Underwood; Brian D. Inouye (Ecology, 2023)
The Rocky Mountain Biological Laboratory (RMBL; Colorado, USA) is the site for many research projects spanning decades, taxa, and research fields from ecology to evolutionary biology to hydrology and beyond. Climate is the focus of much of this work and provides important context for the rest. There are five major sources of data on climate in the RMBL vicinity, each with unique variables, formats, and temporal coverage. These data sources include (1) RMBL resident billy barr, (2) the National Oceanic and Atmospheric Administration (NOAA), (3) the United States Geological Survey (USGS), (4) the United States Department of Agriculture (USDA), and (5) Oregon State University's PRISM Climate Group. Both the NOAA and the USGS have automated meteorological stations in Crested Butte, CO, ~10 km from the RMBL, while the USDA has an automated meteorological station on Snodgrass Mountain, ~2.5 km from the RMBL. Each of these data sets has unique spatial and temporal coverage and formats. Despite the wealth of work on climate-related questions using data from the RMBL, previous researchers have each had to access and format their own climate records, make decisions about handling missing data, and recreate data summaries. Here we provide a single curated climate data set of daily observations covering the years 1975-2022 that blends information from all five sources and includes annotated scripts documenting decisions for handling data. These synthesized climate data will facilitate future research, reduce duplication of effort, and increase our ability to compare results across studies. The data set includes information on precipitation (water and snow), snowmelt date, temperature, wind speed, soil moisture and temperature, and stream flows, all publicly available from a combination of sources. In addition to the formatted raw data, we provide several new variables that are commonly used in ecological analyses, including growing degree days, growing season length, a cold severity index, hard frost days, an index of El Niño-Southern Oscillation, and aridity (standardized precipitation evapotranspiration index). These new variables are calculated from the daily weather records. As appropriate, data are also presented as minima, maxima, means, residuals, and cumulative measures for various time scales including days, months, seasons, and years. The RMBL is a global research hub. Scientists on site at the RMBL come from many countries and produce about 50 peer-reviewed publications each year. Researchers from around the world also routinely use data from the RMBL for synthetic work, and educators around the United States use data from the RMBL for teaching modules. This curated and combined data set will be useful to a wide audience. Along with the synthesized combined data set we include the raw data and the R code for cleaning the raw data and creating the monthly and yearly data sets, which facilitate adding additional years or data using the same standardized protocols. No copyright or proprietary restrictions are associated with using this data set; please cite this data paper when the data are used in publications or scientific events.

Dispersal of the golden-mantled ground squirrel - N. T. Nguyen (2023)
Dispersal, the permanent movement of an animal away from its location of birth, is common in mammals and can have an important role in shaping demography, genetics, distribution, and social structure. Dispersal entails potential costs but also potential benefits, and the dispersal decision is thought to be conditional; the potential disperser assesses prospects for success at its current location and disperses to improve its fitness. However, the costs and benefits of dispersal, as well as factors influencing the dispersal decision, are not well known. We used trapping and observation to study dispersal in the Golden-mantled Ground Squirrel (Callospermophilus lateralis), a species for which dispersal is largely unknown. We characterized the dispersal process by evaluating dispersal timing and distance, assessed factors that might influence the dispersal decision, and analyzed the fitness cost of dispersal after settlement. We found that most dispersal occurred during the summer of birth, as is expected for a small-bodied sciurid. However, some squirrels delayed dispersal until early in their yearling summer. Dispersal was male-biased in dispersal tendency, and it was also male-biased in dispersal distance, but only over shorter dispersal distances. The dispersal decision for juvenile females appeared to originate as soon as 10 days after they emerged from the natal burrow, and the decision was not associated with body mass or several measures of competition. Instead, dispersal of juvenile females was associated with the number of littermate sisters, with each sister present increasing the likelihood of dispersal by 26%. Littermate sisters might be a cue foretelling the effects of kin competition the following year. We did not find a significant difference in lifetime reproductive success between philopatric and dispersing females after settlement, suggesting that for Golden-mantled Ground Squirrels, any cost of dispersal is experienced primarily during the transience phase. iv

Monazite and xenotime petrochronologic constraints on four Proterozoic tectonic episodes and ca. 1705 Ma age of the Uncompahgre Formation, southwestern Colorado, USA - A. Kate Souders; Ian W. Hillenbrand; Kaitlyn A. Suarez; Michael J. Jercinovic; Heather A. Lowers; Karl E. Karlstrom; Michael L. Williams (Geosphere, 2023)
Abstract The Proterozoic tectonic evolution of the southwestern USA remains incompletely understood due to limited constraints on the timing and conditions of the tectono-metamorphic phases and depositional age of metasedimentary successions. We integrated multi-scale compositional mapping, petrologic modeling, and in situ geochronology to constrain pressure-temperature-time paths from samples of Paleoproterozoic basement gneisses and overlying quartzites in southwestern Colorado, USA. Basement gneiss from the western Needle Mountains records metamorphic conditions of 600 °C at 0.75 GPa at 1764 ± 9 Ma and ~575 °C at 1741 ± 10 Ma. Gneiss sampled from drill core near Pagosa Springs, Colorado, records conditions of 700 °C at 1748 ± 9 Ma, 800 °C at 1.1 GPa at 1650 ± 40 Ma, 540 °C at 1570 ± 36 Ma, and 440 °C at 1424 ± 12 Ma. The Uncompahgre Formation was deposited at ca. 1705 Ma, as constrained by detrital monazite (1707 ± 8 Ma) and xenotime (1692 ± 40, 1725 ± 50 Ma), metamorphic xenotime (1650 ± 10 Ma), and published 40Ar/39Ar and detrital zircon data. Compositions of ca. 1705 Ma detrital monazite and xenotime are consistent with derivation from a garnet-bearing source in the Yavapai orogenic hinterland. The Vallecito Conglomerate and Uncompahgre Formation record macroscopic folding and greenschist-facies metamorphism at 1650 ± 10 Ma and temperatures of 270 °C to >570 °C at 1470–1400 Ma. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) zircon geochronology yielded dates of 1775 ± 18 Ma from the Twilight Gneiss and 1696 ± 7 Ma from the Bakers Bridge Granite, supporting previous isotope dilution–thermal ionization mass spectrometry (ID-TIMS) dates. The Eolus Granite yielded a date of 1463 ± 6 Ma, which is older than previous 1.44–1.43 Ga ID-TIMS dates. The newly dated granite of Cataract Gulch is 1421 ± 12 Ma. In situ analysis of detrital and meta-morphic monazite and xenotime, igneous zircon, and quantitative thermobarometry, integrated with previously published constraints, indicate multiple tectonic episodes after the emplacement of 1800–1760 Ma arc-related rocks. The region experienced greenschist- to amphibolite-facies metamorphism (M1) from 1760 Ma to 1740 Ma, which was followed by the intrusion of granites at 1730–1695 Ma and deposition of the Uncompahgre Formation at ca. 1705 Ma, contemporaneous with the Yavapai orogeny. Metamorphism at 1680–1600 Ma was characterized by greenschist-facies conditions near Ouray, Colorado, and granulite-facies conditions near Pagosa Springs (M2) during the Mazatzal orogeny. From 1470 Ma to 1400 Ma, greenschist- to amphibolite-facies metamorphism (M3) and largely granitic plutonism occurred during the protracted Picuris orogeny. These results demonstrate the power of monazite and xenotime analyses to constrain depositional ages, provenance, and pressure-temperature-time (P-T-t) paths to resolve the compound orogenic history that is characteristic of most mountain belts.

Biden Administration Considers Unprecedented Solution to Colorado River Crisis - Jane Palmer (Eos, 2023)
As Colorado River Basin states prove unable to reach a consensus in reducing their water consumption, the U.S. Department of the Interior is investigating an option that defies the Law of the River.

Late Pleistocene Herpetofauna from Two High-Elevation Caves in the Upper Gunnison Basin, Colorado - Jim I. Mead; Steven D. Emslie; David J. Meltzer (Western North American Naturalist, 2023)
Las cuevas Cement Creek y Haystack en Colorado han producido un diverso registro de mamíferos de gran altitud del Cuaternario tardío. Entre los abundantes restos de mamíferos, se registraron raros casos de anfibios y reptiles, los cuales reportamos a continuación. En la cueva Cement Creek (2860 m de elevación) se encontraron solo unos pocos anuros y un número limitado de serpientes. Mientras que, en la cueva Haystack, a una elevación sustancialmente más baja (2450 m de elevación), se encontraron una salamandra, una mayor cantidad de serpientes y una gran cantidad de restos de lagartos, pero no anuros. Las dos faunas son distintas en su composición en general y, aunque no son diversas ni abundantes en términos de especies o número de restos de fauna, proporcionan un registro único y excepcional de una herpetofauna de alta elevación del Pleistoceno tardío del oeste intermontañoso.

Evolution of social position and structure – a multilevel selection perspective - Conner S. Philson (2023)

Effects of Altitude on the Growth, Mortality, and Recruitment of Subalpine Tree Species in the West Elk Mountains of Colorado. - J. Budoff-Corujo (2023)
Subalpine ecosystems in Colorado occur between 9,000-11,000ft in elevation and are composed of several species of conifers. The elevation range of each species is slightly different, but they tend to form established communities, such as the Engelmann spruce-subalpine fir community. It has been shown that many plant species adjust their range differently as the climate changes, leading to potential concerns about plant community assemblages changing. In this study, we are looking at the ways that different tree species in the subalpine habitat interact with altitude, specifically: Quaking aspen (Populus tremuloides), lodgepole pine (Pinus contorta), subalpine fir (Abies lasiocarpa), Engelmann spruce (Picea engelmannii), and Rocky mountain douglas fir (Pseudotsuga menziesii var. glauca). We established five plots in the West Elk Mountains of Colorado. Each plot was 40 x 40m, and each tree was marked with a tagged number in every plot. A variety of measurements were taken for trees in 2018, and again in 2023. We used some of these measurements to calculate changes in growth, mortality, and recruitment for each of these five species at different elevations. We also used additional data from the Forest Service's Forest Inventory and Analysis database to supplement the data sample. The aim of the study is to see how these five species interact with elevation gradients. Our results did not indicate that there was a relationship between either mortality or recruitment and elevation, and there is most likely other factors more important in determining these things. However, there did seem to be a negative relationship between elevation and growth, in the form of DBH growth rate per year and basal area growth rate per year. Our FIA data analysis also confirmed this negative relationship between growth and elevation. Finally analysis of some of the FIA data shows an increase in mortality from 2012-2019 when compared to 2002-2011.

Virtually the Same? Evaluating the Effectiveness of Remote Undergraduate Research Experiences - S. Palchoudhury; A. Osano; Arthur E. Smith; C. A. Shaw; M. Minkara; M. J. Eggers; F. Tsien; D. Jensen-Ryan; V. A. Doze; E. L. Dolan; J. Disney; O. A. Erickson; et al. (Life Sciences Education, 2023)
In-person undergraduate research experiences (UREs) promote students’ integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration and whether they might perceive doing research less favorably (i.e., not beneficial or too costly). To address these questions, we examined indicators of scientific integration and perceptions of the benefits and costs of doing research among students who participated in remote life science URE programs in Summer 2020. We found that students experienced gains in scientific self-efficacy pre- to post-URE, similar to results reported for in-person UREs. We also found that students experienced gains in scientific identity, graduate and career intentions, and perceptions of the benefits of doing research only if they started their remote UREs at lower levels on these variables. Collectively, students did not change in their perceptions of the costs of doing research despite the challenges of working re- motely. Yet students who started with low cost perceptions increased in these perceptions. These findings indicate that remote UREs can support students’ self-efficacy development, but may otherwise be limited in their potential to promote scientific integration.

Looking through leftovers: an analysis of bee bowl bycatch - E. Brandon (2023)
In this lab I analyzed the species composition of arthropods in bee bowl bycatch. The results of an analysis of these different communities show a significant difference in the compositional Orders of arthropods found in both the bowl colors and among the different sites along an elevational gradient. Examining the community composition of arthropods caught as bycatch in bee bowl traps provides an opportunity to collect and analyze data that is useful for asking new questions regarding community composition at different study sites, local interactions among biotic and abiotic factors, seasonal changes in community composition, and for long term studies in the effects of climate change on arthropod communities. To answer these questions more studies like this should be done to examine arthropod communities.

Skewness in bee and flower phenological distributions - R. G. Dickson; Pardee G.; Sean R. Griffin; M. Stemkovski; Rebecca E. Irwin; N. C. Underwood; David W. Inouye; Brian D. Inouye (Ecology, 2023)
Phenological distributions are characterized by their central tendency, breadth, and shape, and all three determine the extent to which interacting species overlap in time. Pollination mutualisms rely on temporal co-occurrence of pollinators and their floral resources, and although much work has been done to characterize the shapes of flower phenological distributions, similar studies that include pollinators are lacking. Here, we provide the first broad assessment of skewness, a component of distribution shape, for a bee community. We compare skewness in bees to that in flowers, relate bee and flower skewness to other properties of their phenology, and quantify the potential consequences of differences in skewness between bees and flowers. Both bee and flower phenologies tend to be right-skewed, with a more exaggerated asymmetry in bees. Early-season species tend to be the most skewed, and this relationship is also stronger in bees than in flowers. Based on a simulation experiment, differences in bee and flower skewness could account for up to 14% of pairwise overlap differences. Given the potential for interaction loss, we argue that difference in skewness of interacting species is an underappreciated property of phenological change.

The social microbiome: gut microbiome diversity and abundance are negatively associated with sociality in a wild mammal - S. R. Tennenbaum; M. Pfau; G. C. Johnson; S. Degregori; P. H. Barber; Conner S. Philson; Daniel T. Blumstein (Royal Society Open Science, 2023)
The gut microbiome has a well-documented relationship with host fitness. Greater microbial diversity and abundance of specific microbes have been associated with improved fitness outcomes. Intestinal microbes also may be associated with patterns of social behaviour. However, these associations have been largely studied in captive animal models; we know less about microbiome composition as a potential driver of individual social behaviour and position in the wild. We used linear mixed models to quantify the relationship between fecal microbial composition, diversity and social network traits in a wild population of yellow-bellied marmots (Marmota flaviventer). We focused our analyses on microbes previously linked to sociability and neurobehavioural alterations in captive rodents, primates and humans. Using 5 years of data, we found microbial diversity (Shannon-Wiener and Faith's phylogenetic diversity) has a modest yet statistically significant negative relationship with the number of social interactions an individual engaged in. We also found a negative relationship between Streptococcus spp. relative abundance and two social network measures (clustering coefficient and embeddedness) that quantify an individual's position relative to others in their social group. These findings highlight a potentially consequential relationship between microbial composition and social behaviour in a wild social mammal.

Structure and composition of natural ferrihydrite nano-colloids in anoxic groundwater - J. R. Runyon; O. Qafoku; J. Cliff; J. S. Lozama Pacheco; R. K. Kukkadapu; J. Chorover; L. Kovarik; M. Engel; Vincent Noel; Samuel Pierce; John R. Bargar; Kristin Boye (Water Research, 2023)
Fe-rich mobile colloids play vital yet poorly understood roles in the biogeochemical cycling of Fe in groundwater by influencing organic matter (OM) preservation and fluxes of Fe, OM, and other essential (micro-)nutrients. Yet, few studies have provided molecular detail on the structures and compositions of Fe-rich mobile colloids and factors controlling their persistence in natural groundwater. Here, we provide comprehensive new information on the sizes, molecular structures, and compositions of Fe-rich mobile colloids that accounted for up to 72% of aqueous Fe in anoxic groundwater from a redox-active floodplain. The mobile colloids are multi-phase assemblages consisting of Si-coated ferrihydrite nanoparticles and Fe(II)-OM complexes. Ferrihydrite nanoparticles persisted under both oxic and anoxic conditions, which we attribute to passivation by Si and OM. These findings suggest that mobile Fe-rich colloids generated in floodplains can persist during transport through redox-variable soils and could be discharged to surface waters. These results shed new light on their potential to transport Fe, OM, and nutrients across terrestrial-aquatic interfaces.

Mineralogical, magnetic and geochemical data constrain the pathways and extent of weathering of mineralized sedimentary rocks - S. P. Slotznick; Jeffrey L Mauk; N. L. Swanson-Hysell; S. C. Fakra; Sharon Bone; Jillian F. Banfield; M. C. Sitar; Sergio Carrero; Andrew H Manning; Kenneth Hurst Williams (Geochimica et Cosmochimica Acta, 2023)

Limnephilus externus Case Grazing - B. Baiz (2023)
The subalpine region of Colorado hosts a variety of aquatic habitats. The organisms that inhabit these ecosystems are presented with many ecological adversities and differing predator guilds. Limnephilus externus caddisfly larvae native to montane and subalpine ponds of the Elk Mountains of Colorado face predatory interactions as well as seasonal time constraints. They have adapted to these adversities by engineering intricate casings made from sedge and other pond debris held together with silk. Caddisfly case morphology differs among species to accommodate for a variety of environmental and biotic variables. Tradeoffs and the proper allocation of resources are necessary for the survival of caddisfly larvae to adulthood. Field observations have documented L. externus individuals grazing on their own casings as well as the cases of conspecifics. In this study we take surveys of pond variables such as L. externus densities, predator densities, amount of emergent and marginal sedge cover in percentage and elevation to determine what factors influence L. externus case grazing and case size. A controlled sweater box experiment was conducted to understand the extent that sedge availability impacts case size and case grazing. The results showed that case size increased as sedge availability increased and case grazing increased as sedge availability decreased. We expect that case size will positively correlate with predator abundance and amount of sedge, whereas L. externus density and elevation will negatively correlate with case size.

Herbivory damage but not plant disease under experimental warming is dependent on weather for three subalpine grass species - Ian W. McCowen; Nisreen Abo-Sido; Shermila B. Villanueva; John Harte; Jennifer A. Rudgers; Joshua S. Lynn (Journal of Animal Ecology, 2023)
Abstract Both theory and prior studies predict that climate warming should increase attack rates by herbivores and pathogens on plants. However, past work has often assumed that variation in abiotic conditions other than temperature (e.g. precipitation) do not alter warming responses of plant damage by natural enemies. Studies over short time periods span low variation in weather, and studies over long time‐scales often neglect to account for fine‐scale weather conditions. Here, we used a 20+ year warming experiment to investigate if warming affects on herbivory and pathogen disease are dependent on variation in ambient weather observed over 3 years. We studied three common grass species in a subalpine meadow in the Colorado Rocky Mountains, USA. We visually estimated herbivory and disease every 2 weeks during the growing season and evaluated weather conditions during the previous 2‐ or 4‐week time interval (2‐week average air temperature, 2‐ and 4‐week cumulative precipitation) as predictors of the probability and amount of damage. Herbivore attack was 13% more likely and damage amount was 29% greater in warmed plots than controls across the focal species but warming treatment had little affect on plant disease. Herbivory presence and damage increased the most with experimental warming when preceded by wetter, rather than drier, fine‐scale weather, but preceding ambient temperature did not strongly interact with elevated warming to influence herbivory. Disease presence and amount increased, on average, with warmer weather and more precipitation regardless of warming. Synthesis . The effect of warming over reference climate on herbivore damage is dependent on and amplified by fine‐scale weather variation, suggesting more boom‐and‐bust damage dynamics with increasing climate variability. However, the mean effect of regional climate change is likely reduced monsoon rainfall, for which we predict a reduction in insect herbivore damage. Plant disease was generally unresponsive to warming, which may be a consequence of our coarse disease estimates that did not track specific pathogen species or guilds. The results point towards temperature as an important but not sufficient determinant and regulator of species interactions, where precipitation and other constraints may determine the affect of warming.

Biofluorescence in Polymorphic Tiger Salamanders ( Ambystoma mavortium nebulosum) - T. Neufell (2023)
Animal communication is vital to nearly every species. Serving multiple functions and being conveyed throughout a variety of modes, communication allows animals to make decisions based on information other animals provide. Numerous examples of this can be found across the animal kingdom, with biofluorescence being a newly investigated form of visual communication. Biofluorescence is the absorption and remission of light by a living organism that generates a fluorescent hue of various colors. Heavily studied in marine species, little is known about the mechanism and function of biofluorescence in tetrapods. Recently, biofluorescent sexual dimorphism was discovered in a species of salamander which prompts the question if their fluorescent response could be used as a form of reproductive visual communication. I explored this topic through the study of biofluorescence in Ambystoma mavortium nebulosum, a polymorphic salamander subspecies that is capable of successfully interbreeding between morphs. To accomplish this, I photographed both sexes of metamorphic and paedomorphic salamanders under blue-excitation light to visualize fluorescent patterns and compared their torso similarities using pattern recognition software (I3SPattern+). After quantifying pattern similarities, biofluorescent morph differences were found on the dorsal and ventral side of the animal’s torso with no differences detected across the sexes. As far as I know, this is the first study investigating biofluorescence in a polymorphic species. While the ecological function of biofluorescence in salamanders remains unknown, understanding the expression of biofluorescence in this subspecies has increased our knowledge of this phenomenon and provided us with more insight into salamander reproductive communication.

A new Eocene cockroach species from the Green River Formation of Colorado, U.S.A. - David Zelagin; Peter Barna; Lucia Šmídová (Biologia, 2023)

Climate lags and genetics determine phenology in quaking aspen (Populus tremuloides) - M. Exposito-Alonso; J. A. Walton; Benjamin Blonder; S. Hateley; M. Moon; Erin Carroll; Philip G. Brodrick; H. Tran; K. Dana Chadwick; R. M. Cruz-de Hoyos (New Phytologist, 2023)
Spatiotemporal patterns of phenology may be affected by mosaics of environmental and genetic variation. Environmental drivers may have temporally lagged impacts, but patterns and mechanisms remain poorly known. We combine multiple genomic, remotely sensed, and physically modeled datasets to determine the spatiotemporal patterns and drivers of canopy phenology in quaking aspen, a widespread clonal dioecious tree species with diploid and triploid cytotypes. We show that over 391 km2 of southwestern Colorado: greenup date, greendown date, and growing season length vary by weeks and differ across sexes, cytotypes, and genotypes; phenology has high phenotypic plasticity and heritabilities of 31-61% (interquartile range); and snowmelt date, soil moisture, and air temperature predict phenology, at temporal lags of up to 3 yr. Our study shows that lagged environmental effects are needed to explain phenological variation and that the effect of cytotype on phenology is obscured by its correlation with topography. Phenological patterns are consistent with responses to multiyear accumulation of carbon deficit or hydraulic damage.

Season Of The Chanterelles And Other Stories - Kirsten Ferguson (2023)
This collection of short literary fiction springs loosely from a contemplation of the enduring influence of Washington Irving’s Gothic in the Hudson Valley. The first story, “Life Is Good,” centers on a fictionalized account of a morbidly obese bear named Allen and a resilient child, Henny, who forms an unlikely bond with the captive animal, reflecting on themes of nature, independence, and abandonment. The second story, “Recipes for Radicals,” delves into the COVID-19 pandemic with a diary-like structure and an underlying theme of confronting moral injustices and the complexities of justice and revenge. In “The Wild Thing,” the protagonist, Meredith, navigates the contradictions of her feelings in working for a morally bereft socialite, and her ultimate decision to choose integrity over loyalty. The final two stories, “A Very Special Murder” and “Season of the Chanterelles,” explore the danger and diversity of nature, including ominous aspects of the natural world that surpass human agency. Throughout the collection, the works of fiction authors such as Emily Dickinson, Carmen Maria Machado, David Means, and Truman Capote serve as inspiration, highlighting the power of nature and the boundaries of human art in capturing its awe and mystery.

Exploring the impact of climate change on soil carbon storage in montane meadows - E. Waldron (2023)
The excess of greenhouse gasses like carbon dioxide in the atmosphere urgently calls for a deeper understanding of existing natural mechanisms for carbon sequestration. Montane meadows act as a critical natural carbon sink, often having the capacity to store much more carbon in their soils than surrounding ecosystems. However, many factors associated with climate change can impact soil carbon storage processes, converting carbon sinks to carbon sources. This can be especially problematic in montane meadows because of their relatively high soil carbon content. This study uses experimental treatments to ask how soil carbon storage may be impacted by three factors associated with climate change: warming, shifts in plant community composition, and early snowmelt. I investigated these questions by measuring soil organic carbon (SOC), and by taking soil temperature and moisture data to understand the mediating influence of these factors on soil carbon storage. I found that although none of the treatments affected total SOC, warming and changes in plant community composition shifted the distribution of SOC along the soil horizon. SOC seemed to shift to shallower soil under these ecologically relevant treatments, which is worrying because carbon tends to be less stable in shallow soils compared to deep soils. Climate change may therefore be destabilizing carbon stores in a critical carbon sink.

How season length and diet breadth limit mason bee success across an elevational gradient - R. Tripathy (2023)

Dead in the Water? Addressing the Future of Water Conservation in the Colorado River Basin - Harmukh Singh (SSRN Electronic Journal, 2023)

Time's Arrow and the Things We Leave Behind: What Harriet G. Barclay’s Herbarium Collections can Teach us about her life and the land she studied - E. Lombardi (2023)

Demographic responses of hybridizing cinquefoils to changing climate in the Colorado Rocky Mountains - M. F. Oldfather; Kelly A Carscadden; N. C. Emery; D. F. Doak (Ecology and Evolution, 2023)
Hybridization between taxa generates new pools of genetic variation that can lead to different environmental responses and demographic trajectories over time than seen in parental lineages. The potential for hybrids to have novel environmental tolerances may be increasingly important in mountainous regions, which are rapidly warming and drying due to climate change. Demographic analysis makes it possible to quantify within- and among-species responses to variation in climate and to predict population growth rates as those conditions change. We estimated vital rates and population growth in 13 natural populations of two cinquefoil taxa (Potentilla hippiana and P. pulcherrima) and their hybrid across elevation gradients in the Southern Rockies. Using three consecutive years of environmental and demographic data, we compared the demographic responses of hybrid and parental taxa to environmental variation across space and time. All three taxa had lower predicted population growth rates under warm, dry conditions. However, the magnitude of these responses varied among taxa and populations. Hybrids had consistently lower predicted population growth rates than P. hippiana. In contrast, hybrid performance relative to P. pulcherrima varied with population and climate, with the hybrid maintaining relatively stable growth rates while populations of P. pulcherrima shrank under warm, dry conditions. Our findings demonstrate that hybrids in this system are neither intrinsically unfit nor universally more vigorous than parents, suggesting that the demographic consequences of hybridization are context-dependent. Our results also imply that shifts to warmer and drier conditions could have particularly negative repercussions for P. pulcherrima, which is currently the most abundant taxon in the study area, possibly as a legacy of more favorable historical climates. More broadly, the distributions of these long-lived taxa are lagging behind their demographic trajectories, such that the currently less common P. hippiana could become the most abundant of the Potentilla taxa as this region continues to warm and dry.

Impact of Crosstalk on Reflectivity and Doppler Measurements for the WIVERN Polarization Diversity Doppler Radar - F. E. Scarsi; A. Battaglia; Maximilian Maahn; Heike Kalesse-Los; F. Tridon; A. Rizik; A. Illingworth; Anton Kötsche (IEEE Transactions on Geoscience and Remote Sensing, 2023)
The WIVERN (Wind VElocity Radar Nephoscope) mission, one of the four ESA Earth Explorer 11 candidate missions, aims at globally observing, for the first time, simultaneously vertical profiles of reflectivities and line of sight winds in cloudy and precipitating regions. WIVERN adopts a dual-polarization Doppler radar in order to overcome the short decorrelation time between successive radar pulses transmitted from low Earth-orbiting satellites with finite beamwidth antennas. WIVERN transmits a single polarization state at a time (H or V), receives in both polarization states, and uses the Polarization Diversity Pulse Pair (PDPP) technique to estimate the Doppler velocity. The weaker cross-polar signals can sometimes interfere with the co-polar ones, causing ghost signals in the measurements that hinder the system’s overall performance. Additionally, with the envisaged radar trigger mode, parameters such as Linear Depolarization Ratio (LDR) and Differential Reflectivity (Z DR ) cannot be directly measured because of the nearly simultaneous transmission of H and V pulses. To overcome these challenges, this article presents a novel technique based on the Optimal Estimation (OE) algorithm for retrieving LDR, Z DR , and co-polar reflectivity for radars operated in PDPP mode. The performance of the proposed method is evaluated using a realistic climatology of profiles simulated from CloudSat data. Results demonstrate that co-polar reflectivity can be accurately retrieved in regions with a good signal-to-noise ratio and in the absence of simultaneous cross-talk interference in both channels (which occurs very rarely). The LDR retrieval on the other hand is typically driven by the a-priori with a substantial impact of measurements only for the surface returns. The impact of cross-talk is also assessed on the reduction of precise Doppler measurements. Findings confirm that a selection of the separation between the two polarization diversity pulses ( THV ) of 20 μs achieves a good balance between the large errors originated by the strong dependence on the Doppler phase noise at small THV s and those caused by the drop in correlation and unambiguous Nyquist velocity at large THV .

Individual life histories: neither slow nor fast, just diverse - James A. Mills; John Yarrall; Anne Charmantier; Stéphanie Jenouvrier; Francine M. Mayer; Gaillard J-M; Martijn van de Pol; Christophe Barbraud; Sandra Hamel; Emmanuel Milot; Jay Rotella; Benjamin Larue; et al. (Proceedings of the Royal Society B, 2023)
The slow-fast continuum is a commonly used framework to describe variation in life-history strategies across species. Individual life histories have also been assumed to follow a similar pattern, especially in the pace-of-life syndrome literature. However, whether a slow-fast continuum commonly explains life-history variation among individuals within a population remains unclear. Here, we formally tested for the presence of a slow-fast continuum of life histories both within populations and across species using detailed long-term individual-based demographic data for 17 bird and mammal species with markedly different life histories. We estimated adult lifespan, age at first reproduction, annual breeding frequency, and annual fecundity, and identified the main axes of life-history variation using principal component analyses. Across species, we retrieved the slow-fast continuum as the main axis of life-history variation. However, within populations, the patterns of individual life-history variation did not align with a slow-fast continuum in any species. Thus, a continuum ranking individuals from slow to fast living is unlikely to shape individual differences in life histories within populations. Rather, individual life-history variation is likely idiosyncratic across species, potentially because of processes such as stochasticity, density dependence, and individual differences in resource acquisition that affect species differently and generate non-generalizable patterns across species.

Agonistic and affiliative social relationships are associated with marmot docility but not boldness - S. Beckert; Dana M. Williams; Julien G. A. Martin; Daniel T. Blumstein (Animal Behaviour, 2023)
All animals must face predation risks at some points in their lives and individuals may vary in how much risk they are willing to accept. While it is well recognized that sociality is a way to manage risks, and social group size effects are well studied, the specific ways in which different types of social relationships influence individual risk response, such as number of interaction partners or the centrality of an individual's position in their group, are not well understood. We examined how yellow-bellied marmots, Marmota flaviventer, affiliative and agonistic social networks are associated with two repeatable measures of risk-related behaviour: boldness/risk taking, quantified from flight initiation distance to a simulated predator approach, and docility/risk aversion, quantified from response to human trapping and handling. We found that docile individuals were less socially integrated and that certain agonistic, but not affiliative, social network measures that quantified their positions in their networks were associated with individual docility. Animals in tighter agonistic networks were also those who were less docile after controlling for a number of other variables that could explain variation in these traits. We found that boldness was not correlated with an individual's agonistic or affiliative interactions. We conclude that some social network measures are part of a docility syndrome in yellow-bellied marmots. Similar studies in other systems are needed to better understand the importance of agonistic and affiliative relationships in selecting for behavioural syndromes.

Cross-trophic-level dynamics in aquatic ecosystems and their application across ecological contexts - E. M. Johnston (2023)

Determining pollinator behavior differences bumblebees and flies. - B. Chau (2023)
Pollinator behavior is integral to understanding community network interactions. These interactions can serve as a proxy for community health. This study aims to compare the behavior between bumblebee pollinators and fly pollinators. This will take place around the area of Gothic, CO, at an elevation of 2900m. Bumblebees and flies are both common pollinators in the region, and studying their behavior would give us insight into how these species interact within a community.

Agricultural Water Footprints and Productivity in the Colorado River Basin - George B. Frisvold; Dari Duval (Hydrology, 2023)
The Colorado River provides water to 40 million people in the U.S. Southwest, with river basin spanning 250,000 square miles (647,497 km2). Quantitative water rights assigned to U.S. states, Mexico, and tribes in the Colorado Basin exceed annual streamflows. Climate change is expected to limit streamflows further. To balance water demands with supplies, unprecedented water-use cutbacks have been proposed, primarily for agriculture, which consumes more than 60% of the Basin’s water. This study develops county-level, Basin-wide measures of agricultural economic water productivity, water footprints, and irrigation cash rent premiums, to inform conservation programs and compensation schemes. These measures identify areas where conservation costs in terms of foregone crop production or farm income are high or low. Crop sales averaged USD 814 per acre foot (AF) (USD 0.66/m3) of water consumed in the Lower Basin and 131 USD/AF (USD 0.11/m3) in the Upper Basin. Crop sales minus crop-specific input costs averaged 485 USD/AF (USD 0.39/m3) in the Lower Basin and 93 USD/AF (USD 0.08 per m3) in the Upper Basin. The blue water footprint (BWF) was 1.2 AF/USD 1K (1480 m3/USD1K) of water per thousand dollars of crop sales in the Lower Basin and 7.6 AF/USD 1K (9374 m3/USD1K) in the Upper Basin. Counties with higher water consumption per acre have a lower BWF.

Changes in the biofluorescence of Ambystoma mavortium nebulosum with age - L. Crayton (2023)

Social security: Does social position influence flight initiation distance? (2023)
A variety of factors can influence an individual’s antipredator behavior including their group size because simply being around conspecifics may reduce predation risk. Recent work has shown that it is not just being around others, but rather the specific social relationships that individuals have with others may also modulate perceptions of risk and explain variation in a variety of antipredator behaviors. We asked whether and how yellow-bellied marmots’ (Marmota flaviventer) position in their social network explains variation in flight initiation distance (FID). We examined the relationship of both direct and indirect measures of sociality and separated models by age and sex classes to isolate the relationships for individuals with different life histories. Following the “social security” hypothesis, we predicted that more socially connected individuals would have a lower FID. We found that the magnitude and direction to which sociality was associated with FID varied based on age and sex. When examining all age- sex cohorts there was a weak effect of strength on FID: individuals in stronger relationships tolerated closer approaches. When examining each cohort independently, we found adult male’s FID was not associated with any social network measure, while female adults fled at greater distances as degree increased. Yearlings of both sexes, however, seemingly benefited from Commented [TS1]: but the directions of the effects are different for both cohorts. AD * closeness increases stronger social relationships, but only when perceived risk was high. These results are consistent FID in FY, but lowers it in MY. is this not important to include in the abstract? with the social security hypothesis; the degree of social connectedness may explain variation in FID in at least some age and sex cohorts.

Characterization of thermal tolerance in sub-alpine bumblebee species - H. Burke (2023)
Temperature is one of the limiting factors of life, and it influences an organism’s growth, sexual reproduction, sexual determination, distribution, and metabolism. the interaction between temperature and organisms therefore an essential component of their ecology. Temperature impacts organisms in different ways, and some organisms, such as bumblebees, may be especially sensitive to temperature shifts. With the likelihood of climate change causing a gradually warmer world, it is vital to understand how bumblebees will respond. Phenology plays a large role in how an animal interacts with temperature, and I seek to evaluate if and how emergence timing influences thermal tolerance in sub-alpine bumblebee species. Critical thermal minimum (CTmin) and critical thermal maximum (CTmax) measurements were taken for five common species of sub-alpine bumblebees in the field over the course of the summer using laboratory-verified devices. We found that there was considerable difference between species type and thermal tolerance., and that earlier emerging species may have less flexibility in their thermal tolerance ranges than later emerging species. Our preliminary results suggest that phenologically earlier species may be more vulnerable to an increasing intensity and frequency of extreme temperature events under climate change.

Plasticity in Ipomopsis flower color and nectar production over space and time in response to water availability - K. Lam (2023)
Climate change is altering water availability in subalpine ecosystems. Shifts in snowmelt timing and summer monsoonal precipitation, which alter soil moisture, have the capacity to elicit plastic responses in plants. Plasticity in floral traits such as nectar production and flower color can impact pollen transfer and thus fitness in Ipomopsis aggregata, since these traits have been shown to play an important role in facilitating pollinator visitation. Understanding how these traits vary spatially and temporally in response to changes in water availability will better inform how I. aggregata will persist and be distributed in the future. Two studies were conducted to assess variation in nectar production and flower color: a long-term study analyzed temporal variation and a short-term study assessed spatial variation within populations. Snowmelt date and total summer precipitation were used as a proxy for water availability in the long-term study, and soil moisture was used in the short term study. Results from the short-term study suggest there are no significant effects of soil moisture on either flower color or nectar production. Conversely, the long-term study indicates both measures of water availability interacted to impact nectar production and flower color. These results indicate that floral traits respond to variation in water availability across years, however, it is unclear whether these shifts impact pollinator visitation.

Early Snowmelt’s Effects on Floral Traits and Rewards of Two Subalpine Plant Species - C. Searles (2023)
The date of spring snowmelt is advancing in numerous alpine and subalpine ecosystems due to both rising temperatures and reduced snowpack associated with climate change. Snowmelt is a critical source of water for plants in subalpine ecosystems, so changes in snowmelt timing can affect many important traits in subalpine plants. In particular, both floral traits and rewards of subalpine plants can be altered by early snowmelt. While several field studies have examined the effects of snowmelt timing on floral traits and rewards, it is vital to consider numerous species responses since there is high variability in responses to early snowmelt. Examining species that bloom at different points in the season is especially important since they may respond differently to snowmelt timing. This study focuses on two closely related species in the Delphinium genus that have similar floral morphologies but bloom at different points in the season. We used an experimental manipulation of snowmelt timing at a field site in the Rocky Mountains to examine the effects on floral traits and floral rewards. Floral sizem nectar rewards and soil moisture were measured weekly during floral anthesis. Using three years of floral trait data, we found that snowmelt timing was associated with smaller flowers in D. nuttallianum and had no effect on floral size in D. barbeyi. The only significant changes in nectar rewards associated with early snowmelt was higher nectar volume in D. nuttallianum in early snowmelt plots in 2023. We also examined the correlation between soil moisture and floral traits and rewards. In 2023, soil moisture had a positive relationship with floral size and nectar volume and a negative relationship with nectar sugar concentration for both species. In 2021 and 2022, we used less precise soil moisture measurements and found less consistent results. Shifts in floral traits and rewards due to climate change could have consequences for the two Delphinium species and pollinator populations.

Analysis of growth patterns in Conifer stands present in Gothic town - D. Hernandez (2023)
Forest ecology research is being revolutionized with the advent of remote sensing. Remote sensing is more accurate and reliable than previous methods for assessing forest dynamics, so it is important to generate workflows for assessing them. The forests of the Gothic townsite are an underutilized subject of study within the Rocky Mountain Biological Laboratory and the aim of this project is to answer questions of how forests grow and why and create workflows for doing this in other localities using remote sensing data. The conifers present in the Gothic Townsite appear to be decreasing in volume and have had negative height changes. There are environmental factors at play but more work needs to be done to understand the mechanisms behind the decrease in total conifer volume.

Talking Yeast: The characterization of bumblebee- and nectar- specialist yeast volatiles in Corydalis caseana - N. Rodriguez (2023)

Advanced monitoring of soil-vegetation co-dynamics reveals the successive controls of snowmelt on soil moisture and on plant seasonal dynamics in a mountainous watershed - S. S. Hubbard; John Peterson; Emmanuel Leger; Jiancong Chen; Baptiste Dafflon; Nicola Falco; Haruko M. Wainwright; Kenneth Hurst Williams (Frontiers in Earth Science, 2023)
Evaluating the interactions between above- and below-ground processes is important to understand and quantify how ecosystems respond differently to atmospheric forcings and/or perturbations and how this depends on their intrinsic characteristics and heterogeneity. Improving such understanding is particularly needed in snow-impacted mountainous systems where the complexity in water and carbon storage and release arises from strong heterogeneity in meteorological forcing and terrain, vegetation and soil characteristics. This study investigates spatial and temporal interactions between terrain, soil moisture, and plant seasonal dynamics at the intra- and inter-annual scale along a 160 m long mountainous, non-forested hillslope-to-floodplain system in the upper East River Watershed in the upper Colorado River Basin. To this end, repeated UAV-based multi-spectral aerial imaging, ground-based soil electrical resistivity imaging, and soil moisture sensors were used to quantify the interactions between above and below-ground compartments. Results reveal significant soil-plant co-dynamics. The spatial variation and dynamics of soil water content and electrical conductivity, driven by topographic and soil intrinsic characteristics, correspond to distinct plant types, with highest plant productivity in convergent areas. Plant productivity in heavy snow years benefited from more water infiltration as well as a shallow groundwater table depth. In comparison, low snowpack years with an early first bare-ground date, which are linked to an early increase in plant greenness, imply a short period of saturated conditions that leads to lower average and maximum greenness values during the growing season. Overall, these results emphasize the strong impact of snowpack dynamics, and terrain and subsurface characteristics on the heterogeneity in plant type and seasonal dynamics.

Hot and Cold: Assessing the Thermal Limitations of Bumble Bees in a Changing Climate - B. Saunders (2023)
To understand bumblebee thermal limitations a controlled experient was built and tested in different environmental conditions to determine the most stable form of conducting upper and lower thermal trials in the field. The study was conducted at field sites located at the Rocky Mountain Biological Laboratory, CO, USA. We subjected Bombus flavifrons, Bombus bifarius, Bombus appositus, Bombus rufocinctus. Bombus californicus to both upper and lower extreme temperatures. Preliminary trials on nonfocus organisms helped refine experimental procedures. With the data we have accumulated now there are small trends beginning to form relating to ITD and upper extreme temperature limitations.

The (surprising) importance of males in a matrilineal society: behavioural insights from a topological knockout study - F. Zenth; S. Gee; A. Solis; Adriana A. Maldonado-Chaparro; Daniel T. Blumstein (Animal Behaviour, 2023)
Social group structure often has consequences for individual fitness and ecological and evolutionary processes, but group structure is not fixed because of demographic processes: individuals die, disperse or are recruited into social groups. Thus, it is important to understand how demographic social roles and the loss of individuals with different roles modify group structure. We studied yellow-bellied marmots, Marmota flaviventer, and performed a series of statistical/topological knockouts on observed marmot social networks to investigate how the social roles of individuals from specific age–sex categories (adult/yearling, males/females) contribute to group social structure and to ask whether the loss of different roles has varying structural effects. We focused on five central aspects of overall social structure: density, the global clustering coefficient, reciprocity, global degree centrality and the coefficient of variation of strength. Somewhat surprisingly, given that marmots live in matrilines, our knockout results suggested that males played a key role in shaping networks: yearling males were a key cohesive element and adult males were central players in agonistic networks. Thus, social networks are dynamic and their structure is shaped in the interplay of demographic processes and individual social behaviour.

A mammalian DNA methylation landscape - A. de Mendoza (Science, 2023)
A study of 348 species offers clues into the diversity of mammalian life spans

Emergent social structure is typically not associated with survival in a facultatively social mammal - Conner S. Philson; Daniel T. Blumstein (Biology Letters, 2023)
For social animals, group social structure has important consequences for disease and information spread. While prior studies showed individual connectedness within a group has fitness consequences, less is known about the fitness consequences of group social structure for the individuals who comprise the group. Using a long-term dataset on a wild population of facultatively social yellow-bellied marmots (Marmota flaviventer), we showed social structure had largely no relationship with survival, suggesting consequences of individual social phenotypes may not scale to the group social phenotype. An observed relationship for winter survival suggests a potentially contrasting direction of selection between the group and previous research on the individual level; less social individuals, but individuals in more social groups experience greater winter survival. This work provides valuable insights into evolutionary implications across social phenotypic scales.

Fixing the Flawed Colorado River Compact - David Stewart; Patricia Limerick; James Eklund; Joann Silverstein; Shemin Ge (Eos, 2023)
The 1922 Colorado River Compact ignored available science and overallocated the river’s water, a decision whose effects reverberate today. Now there’s an opportunity to get things right.

Extensive regional variation in the phenology of insects and their response to temperature across North America - L. L. Berzins; K. Cameron; E. Denton; M. Cody; E. Armstrong; M. Belisle; N. Barlow; M. A. Bernard; T. J. Benson; R. D. Dawson; T. A. Brown; I. Ahmed; et al. (Ecology, 2023)
Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if this is a large-scale problem. Here, we examined the assumption that insect taxa show similar responses to temperature at 96 sites in grassy habitats across North America. We sampled insects with Malaise traps during 2019-2021 (N = 1041 samples) and examined the biomass of insects in relation to temperature and time of season. Our samples mostly contained Diptera (33%), Lepidoptera (19%), Hymenoptera (18%), and Coleoptera (10%). We found strong regional differences in the phenology of insects and their response to temperature, even within the same taxonomic group, habitat type, and time of season. For example, the biomass of nematoceran flies increased across the season in the central part of the continent, but it only showed a small increase in the Northeast and a seasonal decline in the Southeast and West. At a smaller scale, insect biomass at different traps operating on the same days was correlated up to ~75 km apart. Large-scale geographic and phenological variation in insect biomass and abundance has not been studied well, and it is a major source of controversy in previous analyses of insect declines that have aggregated studies from different locations and time periods. Our study illustrates that large-scale predictions about changes in insect populations, and their causes, will need to incorporate regional and taxonomic differences in the response to temperature.

Urban Water Conservation Success in the Colorado River Basin - Jane Palmer (Eos, 2023)
In the past few decades, cities in Arizona, Colorado, and Nevada have vastly increased their water use efficiency. They’ve also learned lessons that can inform other cities’ efforts.

Climate disruption on avian species and communities in the southern Rocky Mountains - L. Gowens (2023)
Climate change is altering the phenology and distribution of organisms across taxonomic groups. Abiotic factors vary along elevational gradients, including those that are affected heavily by climate change, especially temperature. In high elevation environments, species distributions are often limited by temperature, and upward range shifts occur as a response to climate warming. Surveys along elevational gradients can act as a basis to assess these range shifts and enable further investigation of population declines and extinction risks. This study analyzes Gothic Breeding Bird Survey data conducted in 23 years since 1999 to determine long-term changes in species abundance in the southern Rocky Mountains and resurveys points along an elevational gradient (2,469-3,421m) to assess shifts in species elevation range and changes in community composition compared to 2011 survey data and historical ranges. Species abundance analyses of Breeding Bird Survey data indicate that there is a complex relationship between climate disruption and trends in species abundance. Point count survey observations suggest that species may be shifting their ranges upwards when compared to historical ranges, however, comparison to 2011 observations produced a variety of results and indicates that avian species are not uniformly responding to climate disruption with an upward range shift.

The role of environmental variation in mediating fitness trade-offs for an amphibian polyphenism - Sean C. Thomas; K. E. Reider; M. A. Kirk; A. C. R. Lackey; Howard Whiteman (Journal of Animal Ecology, 2023)
AbstractFitness trade‐offs are a foundation of ecological and evolutionary theory because trade‐offs can explain life history variation, phenotypic plasticity, and the existence of polyphenisms.Using a 32‐year mark‐recapture dataset on lifetime fitness for 1093 adult Arizona tiger salamanders (Ambystoma mavortium nebulosum) from a high elevation, polyphenic population, we evaluated the extent to which two life history morphs (aquatic paedomorphs vs. terrestrial metamorphs) exhibited fitness trade‐offs in breeding and body condition with respect to environmental variation (e.g. climate) and internal state‐based variables (e.g. age).Both morphs displayed a similar response to higher probabilities of breeding during years of high spring precipitation (i.e. not indicative of a morph‐specific fitness trade‐off). There were likely no climate‐induced fitness trade‐offs on breeding state for the two life history morphs because precipitation and water availability are vital to amphibian reproduction.Body condition displayed a contrasting response for the two morphs that was indicative of a climate‐induced fitness trade‐off. While metamorphs exhibited a positive relationship with summer snowpack conditions, paedomorphs were unaffected. Fitness trade‐offs from summer snowpack are likely due to extended hydroperiods in temporary ponds, where metamorphs gain a fitness advantage during the summer growing season by exploiting resources that are unavailable to paeodomorphs. However, paedomorphs appear to have the overwintering fitness advantage because they consistently had higher body condition than metamorphs at the start of the summer growing season.Our results reveal that climate and habitat type (metamorphs as predominately terrestrial, paedomorphs as fully aquatic) interact to confer different advantages for each morph. These results advance our current understanding of fitness trade‐offs in this well‐studied polyphenic amphibian by integrating climate‐based mechanisms. Our conclusions prompt future studies to explore how climatic variation can maintain polyphenisms and promote life history diversity, as well as the implications of climate change for polyphenisms.

DNA methylation networks underlying mammalian traits - T. R. Robeck; K. Belov; J. Ablaeva; J. Zhang; D. M. Adams; J. Almunia; P. Black; A. Aloysius; G. Banks; C. Z. Li; A. N. Alagaili; R. Ardehali; et al. (Science, 2023)
Using DNA methylation profiles (n = 15,456) from 348 mammalian species, we constructed phyloepigenetic trees that bear marked similarities to traditional phylogenetic ones. Using unsupervised clustering across all samples, we identified 55 distinct cytosine modules, of which 30 are related to traits such as maximum life span, adult weight, age, sex, and human mortality risk. Maximum life span is associated with methylation levels in HOXL subclass homeobox genes and developmental processes and is potentially regulated by pluripotency transcription factors. The methylation state of some modules responds to perturbations such as caloric restriction, ablation of growth hormone receptors, consumption of high-fat diets, and expression of Yamanaka factors. This study reveals an intertwined evolution of the genome and epigenome that mediates the biological characteristics and traits of different mammalian species.

Pollinator and habitat-mediated selection as potential contributors to ecological speciation in two closely related species - Madison Crowell; J. M. Powers; Diane R. Campbell (Evolution Letters, 2023)
In ecological speciation, incipient species diverge due to natural selection that is ecologically based. In flowering plants, different pollinators could mediate that selection (pollinator-mediated divergent selection) or other features of the environment that differ between habitats of 2 species could do so (environment-mediated divergent selection). Although these mechanisms are well under- stood, they have received little rigorous testing, as few studies of divergent selection across sites of closely related species include both floral traits that influence pollination and vegetative traits that influence survival. This study employed common gardens in sites of the 2 parental species and a hybrid site, each containing advanced generation hybrids along with the parental species, to test these forms of ecological speciation in plants of the genus Ipomopsis. A total of 3 vegetative traits (specific leaf area, leaf trichomes, and photosynthetic water-use efficiency) and 5 floral traits (corolla length and width, anther insertion, petal color, and nectar pro- duction) were analyzed for impacts on fitness components (survival to flowering and seeds per flower, respectively). These traits exhibited strong clines across the elevational gradient in the hybrid zone, with narrower clines in theory reflecting stronger selection or higher genetic variance. Plants with long corollas and inserted anthers had higher seeds per flower at the Ipomopsis tenuituba site, whereas selection favored the reverse condition at the Ipomopsis aggregata site, a signature of divergent selection. In contrast, no divergent selection due to variation in survival was detected on any vegetative trait. Selection within the hybrid zone most closely resembled selection within the I. aggregata site. Across traits, the strength of divergent selection was not significantly correlated with width of the cline, which was better predicted by evolvability (standardized genetic variance). These results support the role of pollinator-mediated divergent selection in ecological speciation and illustrate the importance of genetic variance in determining divergence across hybrid zones.

Effects of Daily Temperature Changes on Broad-Tailed Hummingbird Foraging Patterns - C. Kim; M. Thurber; T. Ngo (2023)
Climate change threatens the close relationship between wildflowers and the hummingbirds that pollinate them, both through gradual warming that shifts and misaligns their phenologies, and also potentially through increasingly erratic day-to-day temperature changes, a phenomenon especially apparent at high altitudes. We investigate how these temperature changes affect the flower visitation rate of broad-tailed hummingbirds (Selasphorus platycercus) in high-elevation Gothic, Colorado, where a significant portion of the birds’ marginal energy budget is spent on thermoregulation. We hypothesize that on days much colder than average, hummingbird visitation will increase as the birds have higher energy demands to thermoregulate. Using hummingbird visitation data collected on cameras around Gothic from 2018-2022 and temperature highs and lows recorded in Gothic weather data from 2016-2022, we calculate visitation deviation from the average on a given day, plotting it against temperature deviation from the average on the same day to explore the relationship between the two variables. We found that there was no evidence of a relationship between short-term temperature changes and hummingbird visitation rate. Temperature did not seem to have an effect on foraging patterns for male or female Broad-tailed hummingbirds in Gothic from 2018 to 2022.

A pathogen's spatial range is not constrained by geographical features in the flax rust pathosystem - Keenan Duggal; C. Jessica Metcalf; Juliana Jiranek (Ecology and Evolution, 2023)
Climate change and shifting environmental conditions can allow pathogens to spread into previously unburdened areas. For plant pathogens, this dynamic has the potential to disrupt natural ecosystem equilibria and human agriculture, making predicting plant pathogen range shifts increasingly important. Although such predictions will hinge on an accurate understanding of the determinants of pathogen range-namely the environmental, geographical, and host range characteristics that modulate local pathogen habitation-few studies to date have probed these in natural plant populations. Here, we characterize range determinants for the model system of Lewis flax (Linum lewisii) and its pathogen, flax rust (Melampsora lini), in the Rocky Mountains. Transect surveys were performed to assess three relationships: (i) the effect of geographical features-elevation, slope aspect, slope grade, and land cover-on flax presence and density, (ii) the effect of geographical features on flax rust presence and prevalence, and (iii) the effects of flax's local population density and metapopulation structure on flax rust presence and prevalence. We found that flax population density, but not host metapopulation structure, influences the distribution of flax rust. Additionally, we showed that, while the distribution of flax was broadly constrained to a relatively narrow range of geographical and resulting environmental features, flax rust was evenly distributed across the full range of settings measured. These results indicate that a warming environment, which is expected to modulate such features, may restrict the optimal range of the plant more than that of its pathogen. Importantly, our results also suggest that even if flax shifts its spatial range to escape increasing climatic pressures, flax rust will not face any significant barriers to track this movement.

Hyporheic Oxygen Dynamics in the East River, Colorado: Insights From an In‐Situ, High Frequency Time Series During Two Distinct Flow Seasons - Vivek Philip; Michael N. Gooseff; Ruby N. Ghosh; M. Evan Matusz; Charles McIntire; Erin Cantrell (Water Resources Research, 2023)
AbstractDissolved oxygen (DO) is critical for aquatic ecosystems, however, few studies have focused on the long‐term DO dynamics in hyporheic zones, which are a function of both transport (hydrologic exchange between river and hyporheic zone) and uptake by biogeochemical reactions or respiration. We explore the dynamics of temperature and DO at 10, 20, and 35 cm depth beneath the East River, Colorado, from July–October 2017 (relatively normal water year) and April to October 2018 (comparatively low flow year), enabled by distinctive, in‐situ, high frequency (Δt = 5 min) sensors that provided continuous time‐series from the undisturbed study site over 14 months. We expect that hyporheic DO, which has a regular daily fluctuation pattern, is supplied by the surface water (at all times we estimate downwelling) and that diurnal hyporheic DO temporal patterns should be aligned with diurnal hyporheic temperature patterns. However, this was not found to be the case. Hyporheic DO becomes depleted briefly at 20 and 35 cm depths in 2017, and at all three hyporheic depths for extended periods in 2018. Whereas diurnal temperature fluctuations have consistent timings of maxima and minima, hyporheic DO rarely has as regular a pattern, and daily ranges are inconsistent. Rainfall events caused some of these changes to diurnal hyporheic DO patterns without repeatable effects. Antecedent snowpack conditions influence streamflow dynamics and therefore hyporheic DO dynamics in this alpine river. These results also point to the strong and variable influence of hyporheic microbial communities regulating hyporheic DO.

Effects of warming, dominant species removal, and accelerated snowmelt on aboveground plant traits in the Colorado Rocky Mountains - Z. Piedra (2023)
Noticeable changes such as the alteration of ecosystem productivity, the influence of species interactions with one another and its environment, and the transformation of habitats are all linked to climate change. Although plant functions might be a useful tool in understanding plant communities and ecosystems, it’s time-consuming and expensive. Instead, we can observe aboveground plant traits, which are virtual indicators of the health conditions of plant communities. Measuring how plant traits respond to global change drivers is a useful way to predict plant and ecosystem functioning in future climates. For example, Plant height is a proxy for light capture, and leaf mass per area (LMA) is a great indicator of leaf photosynthetic capacity. We aimed to discover the effects of warming, dominant species removal and accelerated snowmelt on aboveground plant traits in the Colorado Rocky Mountains. This project took place in a montane meadow in Almont, Colorado where the warming and dominant species removal experiment exists, and in Gothic, Colorado where the accelerated snowmelt manipulation is located. At Almont, we saw that the response of plant height to the experimental treatments depended on the species and a combination of treatments. In total eight out of 15 plant species responded to the treatments in some way. There was also no significant response of leaf mass per area (LMA) to the experimental treatments, instead, LMA depended only on the plant species. There was a similar response of chlorophyll content (SPAD) at Almont, Colorado, where the response depended on the species and the treatments. Contrary to what we found in Almont, in Gothic, Colorado there was no significant response of plant chlorophyll content (SPAD) to the experimental treatments, instead, SPAD depended only on the plant species. These results indicate the complexity of plant trait responses and how dynamic they can be in different locations under numerous climate conditions. Understanding these responses is important because they can help us understand how plant communities in montane meadows might change under future climate scenarios.

Breakfast of champions: Spatiotemporal variation in the quality of ant nests for bear consumers - R. Hunter (2023)
Black bears in the Colorado Rocky Mountains forage for western thatching ants as a food source. However, there is little knowledge about the nutritional benefit of ants for black bears, particularly with regard to changes in nutritional value during the ant life cycle. From late spring to mid-summer, thatching ants go through two separate stages of reproduction that greatly influence the composition of individual ant nests. In early summer, the ant colonies produce sexual ants, resulting in large-bodied immature (larvae and pupae) and adult ants (drones and queens) being present in the nest. During mid to late summer, ant colonies produce nonsexual ants, resulting in smaller immature and adult ants (workers). We conducted a study to measure how these nutritional values change from early to late summer, and how the varying phenology of different locations affects these values. We did this by simulating bear attacks on ant nests in two sites with differing phenology in early summer (June) and late summer (July) and collecting samples from the central brood chamber in each nest. We also wanted to see how a prior bear attack on a nest may affect its nutritional value later in the season, which we addressed by comparing nests that were attacked once (in July) vs. nests that were attacked twice (once in June, once in July). The samples were sorted into castes and life stages of ants (adult worker, pupae, queen, or drone) and weighed. These masses were used to approximate food mass per L of nest material for bears and converted into fat content to measure nutritional value. We found that there was significantly greater total mass and fat content in the ant nests in June compared to July. This was driven by large masses of sexual pupae found within the June nests. We found that there was no significant difference in the nutritional value of nests that were previously attacked vs. those that were not previously attacked. This lack of variation suggests that ant colonies can recover quickly from attacks made by bears, and that bears can revisit ant nests as a replenishable source of food. Altogether, these results indicate that seasonality in ant life cycles should be taken into account when evaluating the nutritional value of ants for bears.

Universal DNA methylation age across mammalian tissues - R. Lowe; Z. Fei; J. Zoller; H. Vu; Qina Yan; J. Almunia; A. Aloysius; G. Banks; K. Belov; D. M. Adams; V. A. Acosta-Rodriguez; T. R. Robeck; et al. (Nature Aging, 2023)
Aging, often considered a result of random cellular damage, can be accurately estimated using DNA methylation profiles, the foundation of pan-tissue epigenetic clocks. Here, we demonstrate the development of universal pan-mammalian clocks, using 11,754 methylation arrays from our Mammalian Methylation Consortium, which encompass 59 tissue types across 185 mammalian species. These predictive models estimate mammalian tissue age with high accuracy (r > 0.96). Age deviations correlate with human mortality risk, mouse somatotropic axis mutations and caloric restriction. We identified specific cytosines with methylation levels that change with age across numerous species. These sites, highly enriched in polycomb repressive complex 2-binding locations, are near genes implicated in mammalian development, cancer, obesity and longevity. Our findings offer new evidence suggesting that aging is evolutionarily conserved and intertwined with developmental processes across all mammals.

Gunnison Sage-Grouse and Mapping Pi - Isa Catto (BioScience, 2023)
Journal Article Gunnison Sage-Grouse and Mapping Pi Get access Isa Catto Isa Catto Aspen, Colorado, United States Search for other works by this author on: Oxford Academic Google Scholar BioScience, Volume 73, Issue 5, May 2023, Page 390, https://doi.org/10.1093/biosci/biad024 Published: 03 April 2023

Host specificity of hemiparasitic Castilleja and its influence on plant community diversity. - M. Lang (2023)
Hemiparasitic plants rely on their hosts for some of their nutritional requirements, but are still able to photosynthesize and absorb water and nutrients through their roots. Parasitic plants have been shown to impact plant community diversity by reducing dominant species' competitive ability, thus allowing for the growth and establishment of secondary, less competitive species. Castilleja is a hemiparasitic genus in the family Orobanchaceae. It forms root haustorial connections with hosts underground. Near The Rocky Mountain Biological Laboratory, there are six common, naturally occurring species of Castilleja. The diversity and specificity of host species of local Castilleja are unknown due to the difficult nature of observing belowground interactions. In this study, we aim to determine the most likely hosts of Castilleja, assess host specificity, and measure Castilleja’s impact on plant diversity and productivity in various Rocky Mountain ecosystems. We found local Castilleja species to be generalists which likely parasitize the most abundant species in the community and that Castilleja presence is positively correlated with plant community diversity and richness, but not evenness.

Community context mediates effects of pollinator loss on seed production - Kaysee Arrowsmith; V. A. Reynolds; Heather M. Briggs (Ecosphere, 2023)
Abstract A critical goal for ecologists is understanding how ongoing local and global species losses will affect ecosystem functions and services. Diversity–functioning relationships, which are well‐characterized in primary producer communities, are much less consistently predictable for ecosystem functions involving two or more trophic levels, particularly in situations where multiple species in one trophic level impact functional outcomes at another trophic level. This is particularly relevant to pollination functioning, given ongoing pollinator declines and the value of understanding pollination functioning for single plant species like crops or threatened plants. We used spatially replicated, controlled single‐pollinator‐species removal experiments to assess how changes in bumble bee species richness impacted the production of fertilized seeds in a perennial herb— Delphinium barbeyi —in the Rocky Mountains of Colorado, USA. To improve predictability, we also assessed how traits and abundances in the plant and bumble bee communities were related to D. barbeyi reproductive success. We hypothesized that trait‐matching between pollinator proboscis length and D. barbeyi 's nectar spurs would produce a greater number of fertilized seeds, while morphological similarity within the floral community would dilute pollination services. We found that the effects of pollinator removal differed depending on the behavioral patterns of pollinators and compositional features of the plant and pollinator communities. While pollinator floral fidelity generally increased D. barbeyi seed production, that positive effect was primarily evident when more than half of the Bombus community was experimentally removed. Similarly, communities comprising primarily long‐tongued bees were most beneficial to D. barbeyi seed production in tandem with a strong removal. Finally, we observed contrasting effects of morphological similarity in the plant community, with evidence of both competition and facilitation among plants. These results offer an example of the complex dynamics underlying ecosystem function in multitrophic systems and demonstrate that community context can impact diversity–functioning relationships between trophic levels.

Aerobic respiration controls on shale weathering - Zhi Li; Lucien Stolze; Benjamin Gilbert; Carl I. Steefel; Dipankar Dwivedi; Markus Bill; Sergio Carrero; Bhavna Arora; P. S. Nico (Geochimica et Cosmochimica Acta, 2023)
The weathering of shale exerts an important control on the hydrochemical fluxes to river systems, thus influencing the global carbon, nutrient, and geochemical cycles. However, the quantitative understanding of shale weathering and its impact on global biogeochemical cycles remains inadequate due to the complex interplay between hydrological, biogeochemical, and physical processes. In this study, we develop a novel modeling approach to quantitatively interpret the long-term chemical weathering of shale occurring since the last glaciation period (15,000 years) leading to the present geochemical conditions. The model explicitly considers processes occurring across multiple phases and involved in the weathering, including: (i) the infiltration of meteoric water, (ii) the interactions between the water and the mineral assemblage via dissolution/precipitation reactions, (iii) the microbially-mediated oxidation of organic matter, (iv) the evolution of porosity induced by mineral reactions, and (v) the exchange of gases between the subsurface and the atmosphere. To implement and test our model, we conduct this study at a well-instrumented hillslope underlain by Mancos Shale and located at the East River study site, Western Colorado. Consistent with field observations, the model successfully reproduces the stratified weathering front, the complex spatial distribution of organic carbon, and the gaseous emissions of carbon dioxide from the subsurface. Model simulations show that aerobic respiration exerts a fundamental control on the weathering of shale. While previous studies have highlighted the diffusion of oxygen from the atmosphere as the primary mechanism for shale weathering, our model simulations demonstrate that aerobic respiration limits the propagation of oxygen in the shallow subsurface, and thereby inhibits the dissolution of pyrite at depth. Aerobic respiration is particularly favored in the top soil horizon due to the constant flux of oxygen from the atmosphere, the replenishment of fresh litter/plant-derived organic matter, and to a lesser extent the presence of fossil shale-associated organic matter. The acidic pore water generated through aerobic respiration within the shallow subsurface is transported to greater depths, where it sustains the dissolution of carbonate (dolomite in this example). Overall, our results demonstrate that the evolution of pyrite and carbonate depletion fronts are significantly different, and primarily depend on the ability of microorganisms to carry out microbial respiration and the various transport pathways of reactants controlling the mineral reactions under partially saturated conditions.

Supporting advancement in weather and water prediction in the upper Colorado River Basin: The SPLASH campaign - A. White; Maciej Stachura; Samuel B. Morris; J. Bytheway; M. Hughes; R. Calmer; Benjamin Schmatz; Jack Elston; Matthew Shupe; K. Lantz; Christian Herrera; Darren Jackson; et al. (Bulletin of the American Meteorological Society, 2023)
Abstract Water is a critical resource that causes significant challenges to inhabitants of the western United States. These challenges are likely to intensify as the result of expanding population and climate-related changes that act to reduce runoff in areas of complex terrain. To better understand the physical processes that drive the transition of mountain precipitation to streamflow, the National Oceanic and Atmospheric Administration has deployed suites of environmental sensors throughout the East River watershed of Colorado as part of the Study of Precipitation, the Lower Atmosphere, and Surface for Hydrometeorology (SPLASH). This includes surface-based sensors over a network of five different observing sites, airborne platforms, and sophisticated remote sensors to provide detailed information on spatiotemporal variability of key parameters. With a 2-yr deployment, these sensors offer detailed insight into precipitation, the lower atmosphere, and the surface, and support the development of datasets targeting improved prediction of weather and water. Initial datasets have been published and are laying a foundation for improved characterization of physical processes and their interactions driving mountain hydrology, evaluation and improvement of numerical prediction tools, and educational activities. SPLASH observations contain a depth and breadth of information that enables a variety of atmospheric and hydrological science analyses over the coming years that leverage collaborations between national laboratories, academia, and stakeholders, including industry. Significance Statement Water is a limited and critical resource in the western United States. To protect water access for millions of people and ecosystems, and to preserve our ability to irrigate millions of acres of cropland, policymakers and water managers require advanced weather and water prediction systems. To improve these forecast systems in high-altitude complex terrain, the National Oceanic and Atmospheric Administration (NOAA) has deployed instrumentation in the East River watershed of the Upper Colorado River basin as part of the Study of Precipitation, the Lower Atmosphere, and Surface for Hydrometeorology (SPLASH). SPLASH observations are being used to advance fundamental understanding of mountain weather and water and to advance predictive capabilities across weather and climate time scales.

Linking microenvironment modification to species interactions and demography in an alpine plant community - Benjamin Blonder; O. H. Opedal (Oikos, 2023)
Individual plants can modify the microenvironment within their spatial neighborhood. However, the consequences of microenvironment modification for demography and species interactions remain unclear at the community scale. In a study of co‐occurring alpine plants, we 1) determined the extent of species‐specific microclimate modification by comparing temperature and soil moisture between vegetated and non‐vegetated microsites for several focal species. We 2) determined how vital rates (survival, growth, fecundity) of all species varied in response to aboveground and belowground vegetative overlap with inter‐ and intraspecific neighbors as proxies for microenvironment modification. For 1), surface temperatures were buffered (lower maximums and higher minimums) and soil moisture was higher below the canopies of most species compared to non‐vegetated areas. For 2), vegetative overlap predicted most vital rates, although the effect varied depending on whether aboveground or belowground overlap was considered. Vital rate response to microenvironment‐modification proxies (vegetative overlap) was also frequently context dependent with respect to plant size and macroclimate. Microenvironment modification and spatial overlapping of individuals are key drivers of demography and species interactions in this alpine community.

Differential response of three large mammal species to human recreation in the Rocky Mountains of Colorado, USA - Shannon Sprott; A. Bermudez; V. Rodriguez; M. W. Tingley; M. R. Uetrecht; D. Novoa; Richard Alexander Smith; J. S. Reithel; Daniel T. Blumstein (Frontiers in Conservation Science, 2023)
Outdoor recreation benefits local economies, environmental education, and public health and wellbeing, but it can also adversely affect local ecosystems. Human presence in natural areas alters feeding and reproductive behaviors, physiology, and population structure in many wildlife species, often resulting in cascading effects through entire ecological communities. As outdoor recreation gains popularity, existing trails are becoming overcrowded and new trails are being built to accommodate increasing use. Many recreation impact studies have investigated effects of the presence or absence of humans while few have investigated recreation effects on wildlife using a gradient of disturbance intensity. We used camera traps to quantify trail use by humans and mid- to large-sized mammals in an area of intense outdoor recreation–the Upper East River Valley, Colorado, USA. We selected five trails with different types and intensities of human use and deployed six cameras on each trail for five weeks during a COVID-enhanced 2020 summer tourism season. We used occupancy models to estimate detectability and habitat use of the three most common mammal species in the study area and determined which human activities affect the habitat use patterns of each species. Human activities affected each species differently. Mule deer ( Odocoileus hemionus ) tended to use areas with more vehicles, more predators, and greater distances from the trailhead, and they were more likely to be detected where there were more bikers. Coyotes ( Canis latrans ) and red foxes ( Vulpes vulpes ) were most likely to use areas where their prey species occurred, and foxes were more likely to be detected where the vegetation was shorter. Humans and their recreational activities differentially influence different species. More generally, these results reinforce that it is unlikely that a single management policy is suitable for all species and management should thus be tailored for each target species.

Molecular nature of mineral-organic associations within redox-active mountainous floodplain sediments - Genevieve Goebel; Malak M. Tfaily; Marco Keiluweit; C. G. Anderson; Patricia Fox; Scott Fendorf; P. S. Nico (ACS Earth and Space Chemistry, 2023)
Floodplains are critical terrestrial–aquatic interfaces that act as hotspots of organic carbon (OC) cycling, regulating ecosystem carbon storage as well as export to riverine systems. Within floodplain sediments, regular flooding and textural gradients interact to create dynamic redox conditions. While anaerobic protection of OC upon burial is a well-recognized carbon storage mechanism in redox-active floodplain sediments, the impact of protective mineral-organic associations is relatively unknown. Here we determined the quantitative importance and chemical composition of mineral-organic associations along well-defined redox gradients emerging from textural variations and depth within meander sediments of the subalpine East River watershed (Gothic, CO). We characterized mineral-organic associations using a combination of sequential extractions, physical fractionation, and high-resolution mass spectrometry. Across the meander, we found that mineral-associated OC constitutes a significant fraction of total OC, and that extractable iron (Fe) and aluminum (Al) phases as well as high-density isolates were strongly correlated with total OC content, suggesting that mineral-organic associations are quantitatively important for floodplain sediment OC protection. Our mass spectrometry results showed OC associated with increasingly ordered Fe and Al phases are relatively enriched in low-molecular weight, oxidized, aromatic compounds. Surprisingly, however, total OC content showed weak or no correlation with indicators of anaerobic protection, such as relatively bioavailable OC pools (water-extractable and particulate OC) or the molecular weight and oxidation state of OC. Overall, this work highlights that protection of OC bound to reactive mineral phases─in addition to anaerobic protection─can play a quantitatively important role in controlling soil carbon storage in redox-active floodplain sediments.

Evaluating 3 decades of precipitation in the Upper Colorado River basin from a high-resolution regional climate model - Alejandro Flores; William Rudisill (Geoscientific Model Development, 2023)
Abstract. Convection-permitting regional climate models (RCMs) have recently become tractable for applications at multi-decadal timescales. These types of models have tremendous utility for water resource studies, but better characterization of precipitation biases is needed, particularly for water-resource-critical mountain regions, where precipitation is highly variable in space, observations are sparse, and the societal water need is great. This study examines 34 years (1987–2020) of RCM precipitation from the Weather Research and Forecasting model (WRF; v3.8.1), using the Climate Forecast System Reanalysis (CFS; CFSv2) initial and lateral boundary conditions and a 1 km × 1 km innermost grid spacing. The RCM is centered over the Upper Colorado River basin, with a focus on the high-elevation, 750 km2 East River watershed (ERW), where a variety of high-impact scientific activities are currently ongoing. Precipitation is compared against point observations (Natural Resources Conservation Service Snow Telemetry or SNOTEL), gridded climate datasets (Newman, Livneh, and PRISM), and Bayesian reconstructions of watershed mean precipitation conditioned on streamflow and high-resolution snow remote-sensing products. We find that the cool-season precipitation percent error between WRF and 23 SNOTEL gauges has a low overall bias (x^ = 0.25 %, s = 13.63 %) and that WRF has a higher percent error during the warm season (x^ = 10.37 %, s = 12.79 %). Warm-season bias manifests as a high number of low-precipitation days, though the low-resolution or SNOTEL gauges limit some of the conclusions that can be drawn. Regional comparisons between WRF precipitation accumulation and three different gridded datasets show differences on the order of ± 20 %, particularly at the highest elevations and in keeping with findings from other studies. We find that WRF agrees slightly better with the Bayesian reconstruction of precipitation in the ERW compared to the gridded precipitation datasets, particularly when changing SNOTEL densities are taken into account. The conclusions are that the RCM reasonably captures orographic precipitation in this region and demonstrates that leveraging additional hydrologic information (streamflow and snow remote-sensing data) improves the ability to characterize biases in RCM precipitation fields. Error characteristics reported in this study are essential for leveraging the RCM model outputs for studies of past and future climates and water resource applications. The methods developed in this study can be applied to other watersheds and model configurations. Hourly 1 km × 1 km precipitation and other meteorological outputs from this dataset are publicly available and suitable for a wide variety of applications.

The Influence of Forest Structure and Composition on Transpiration Rates Among Drought-Stressed Conifer Species in the Upper East River Watershed - B. Golla (2023)
Despite the ecological significance of prominent coniferous forests surrounding RMBL, there are few comprehensive studies on these systems, particularly regarding transpiration dynamics. Their critical role in carbon sequestration, microclimate dynamics, and water resource management in the Upper Colorado River Basin render them subjects of great research interest. With that being said, sustained drought conditions throughout the region are changing energy fluxes within these forests and bringing into question their resilience in increasingly water-limited circumstances. Examining the physiological adaptations and water-use strategies among different conifer species will aid in our understanding of the ways in which forests contribute to a balanced energy budget in the face of changing climatic conditions. The specific focus of this study is on Engelmann Spruce (Picea engelmannii), Subalpine Fir (Abies lasiocarpa), and Lodgepole Pine (Pinus contorta), three dominant conifers within the Upper East River Watershed. This research aims to investigate the variation in transpiration rates among drought stressed conifers in stands with varying species composition and forest structure. The work combines stem-scale trait measurements and high-resolution aerial imagery with unmanned aerial vehicles (drones) to study transpiration dynamics at a landscape level.

Consequences of climate-induced range expansions on multiple ecosystem functions - S. A. Wissinger; J. A. Balik; B. W. Taylor; H. S. Greig (Communications Biology, 2023)
Climate-driven species range shifts and expansions are changing community composition, yet the functional consequences in natural systems are mostly unknown. By combining a 30-year survey of subalpine pond larval caddisfly assemblages with species-specific functional traits (nitrogen and phosphorus excretion, and detritus processing rates), we tested how three upslope range expansions affected species' relative contributions to caddisfly-driven nutrient supply and detritus processing. A subdominant resident species (Ag. deflata) consistently made large relative contributions to caddisfly-driven nitrogen supply throughout all range expansions, thus "regulating" the caddisfly-driven nitrogen supply. Whereas, phosphorus supply and detritus processing were regulated by the dominant resident species (L. externus) until the third range expansion (by N. hostilis). Since the third range expansion, N. hostilis's relative contribution to caddisfly-driven phosphorus supply increased, displacing L. externus's role in regulating caddisfly-driven phosphorus supply. Meanwhile, detritus processing contributions became similar among the dominant resident, subdominant residents, and range expanding species. Total ecosystem process rates did not change throughout any of the range expansions. Thus, shifts in species' relative functional roles may occur before shifts in total ecosystem process rates, and changes in species' functional roles may stabilize processes in ecosystems undergoing change.

Do dandelions compete with native plants for pollinator visits? - P. Salazar (2023)
In Gothic Colorado, the invasive common dandelion or Taraxacum officinale has slowly made its way through the meadows and along the road flourishing as people aid in dispersing its seeds as the wind carries them. Due to this, the focus of this study is to determine if dandelions compete with native plants for pollinators. Temporary plots were placed alongside the Stupid Falls Meadow, the Gothic road, the beaver ponds on the 401 trail, Emerald lake, and the Mexican cut. These temporary plots focused on three native species: Pseudocymopterus montanus, Valeriana occidentalis, and Ranunculus glaberrimus. The plots measured 2x meters and three times a week the plots were observed based on the natural phenology of the plots rotating every 5 minutes between plots. Based on a t-test there was no significant difference in visits between Taraxacum officinale and Pseudocymopterus montanus. The t-test showed that there was a significant difference between Taraxacum officinale and Valeriana occidentalis. Valeriana occidentalis received more visits. There was a significant difference between Taraxacum officinale and Ranunculus glaberrimus based on visits, favoring Taraxacum officinale. This showed that competition for pollinator visits with Taraxacum officinale depends on the plant species being compared to and that sometimes competition between each other is apparent and sometimes there is no competition. More research should be conducted in order to grasp to what extent invasive species have on native communities.

Mineral and metabolic constraints on carbon cycling within and export from mountainous floodplain soils - C. G. Anderson (2023)
MINERAL AND METABOLIC CONSTRAINTS ON CARBON CYCLING WITHIN AND EXPORT FROM MOUNTAINOUS FLOODPLAIN SOILS SEPTEMBER 2023 CAM G. ANDERSON, B.A., UNIVERSITY OF PUGET SOUND B.S., UNIVERSITY OF MINNESOTA M.S., UNIVERSITY OF CALIFORNIA DAVIS Ph.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Marco Keiluweit

Long-term declines in insect abundance and biomass in a subalpine habitat - Rebecca M. Dalton; N. C. Underwood; M. E. Soule; Brian D. Inouye; David W. Inouye (Ecosphere, 2023)
Abstract Recent reports of insect declines have caused concern among scientists and the public. Declines in insect abundance and biomass are ubiquitous across many climatic zones and have been largely attributed to anthropogenic land use intensification and climate change. However, there are few examples of long‐term continuous data in relatively undisturbed environments, as opposed to agricultural landscapes. We sampled insects weekly from 1986 to 2020 in a protected subalpine meadow in Colorado, which is embedded in an undisturbed natural landscape. During the study period, summers became warmer, while winters became drier. Insect biomass declined by ∼47% and abundance declined by ∼61.5% over the last 35 years. Insect declines occurred in concert with changes in climate, as some climate factors were correlated with insect abundance and biomass. Specifically, insect abundance was lower during years with less summer precipitation and winter snowfall, and to a lesser degree with warmer temperatures. In subalpine systems, changes in precipitation and warmer temperatures are expected to continue under climate change; thus, continued insect declines might be expected even in relatively undisturbed habitats.

Genetic mechanisms underlying maladaptation in specialized species interactions - Nitin Ravikanthachari (2023)
Adaptation has been used as the framework to understand the power of

The causes and consequences of pollen defence - S. Rivest (2023)
Animal pollination represents one of the key innovations of the flowering plants, and constitutes

The Surface Atmosphere Integrated Field Laboratory (SAIL) Campaign - T. C. J. Hill; Matthew Tuftedal; C. C. Hume; S. M. Skiles; Jeffrey Deems; John Ward Smith; Adam Theisen; J. M. Creamean; A. Wiedlea; Maxwell Grover; R. C. Sullivan; A. Kennedy; et al. (Bulletin of the American Meteorological Society, 2023)
Abstract The science of mountainous hydrology spans the atmosphere through the bedrock and inherently crosses physical and disciplinary boundaries: land–atmosphere interactions in complex terrain enhance clouds and precipitation, while watersheds retain and release water over a large range of spatial and temporal scales. Limited observations in complex terrain challenge efforts to improve predictive models of the hydrology in the face of rapid changes. The Upper Colorado River exemplifies these challenges, especially with ongoing mismatches between precipitation, snowpack, and discharge. Consequently, the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) user facility has deployed an observatory to the East River Watershed near Crested Butte, Colorado, between September 2021 and June 2023 to measure the main atmospheric drivers of water resources, including precipitation, clouds, winds, aerosols, radiation, temperature, and humidity. This effort, called the Surface Atmosphere Integrated Field Laboratory (SAIL), is also working in tandem with DOE-sponsored surface and subsurface hydrologists and other federal, state, and local partners. SAIL data can be benchmarks for model development by producing a wide range of observational information on precipitation and its associated processes, including those processes that impact snowpack sublimation and redistribution, aerosol direct radiative effects in the atmosphere and in the snowpack, aerosol impacts on clouds and precipitation, and processes controlling surface fluxes of energy and mass. Preliminary data from SAIL’s first year showcase the rich information content in SAIL’s many datastreams and support testing hypotheses that will ultimately improve scientific understanding and predictability of Upper Colorado River hydrology in 2023 and beyond.

Effects of Microclimate Variation on Diversity of Plants and Pollinators - I. Larson (2023)
High alpine ecosystems have heterogeneous topography that provides microclimatic niches for species to inhibit. Due to climate change, alpine ecosystems are experiencing shifts in snowpack amount, snowmelt timing, and growing season lengths resulting in phenological and abundance responses within ecosystems. Although previous studies have focused on various microclimatic effects on plant communities, there is less known about the effect of snowmelt timing on floral abundance and pollinator diversity. This study investigates the effects of microclimate variation on diversity of plants and pollinators. We performed plant phenology and pollinator surveys along two established 50 meter transects at our Judd Falls and Snodgrass sites. Each transect was divided into 2 meter by 2 meter plots, which were observed twice a day for plant and pollinator interactions for a duration of 2 minutes. We found that although plant richness was higher on high microclimate heterogeneity transects, observed pollinator richness and floral abundance was not higher on high heterogeneity transects. However, transects with higher floral abundance had higher pollinator richness, suggesting that bees are responding more strongly to floral abundance than diversity. Our findings are relevant to understanding how microclimate variation is affecting plant and pollinator responses to climate change.

The timing of reproduction is responding plastically, not genetically, to climate change in yellow-bellied marmots (Marmota flaviventer) - S. St. Lawrence; Julien G. A. Martin; Daniel T. Blumstein (Ecology and Evolution, 2023)
With global climates changing rapidly, animals must adapt to new environmental conditions with altered weather and phenology. The key to adapting to these new conditions is adjusting the timing of reproduction to maximize fitness. Using a long-term dataset on a wild population of yellow-bellied marmots (Marmota flaviventer) at the Rocky Mountain Biological Laboratory (RMBL), we investigated how the timing of reproduction changed with changing spring conditions over the past 50 years. Marmots are hibernators with a 4-month active season. It is thus crucial to reproduce early enough in the season to have time to prepare for hibernation, but not too early, as snow cover prevents access to food. Importantly, climate change in this area has, on average, increased spring temperatures by 5°C and decreased spring snowpack by 50 cm over the past 50 years. We evaluated how female marmots adjust the timing of their reproduction in response to changing conditions and estimated the importance of both microevolution and plasticity in the variation in this timing. We showed that, within a year, the timing of reproduction is not as tightly linked to the date a female emerges from hibernation as previously thought. We reported a positive effect of spring snowpack but not of spring temperature on the timing of reproduction. We found inter-individual variation in the timing of reproduction, including low heritability, but not in its response to changing spring conditions. There was directional selection for earlier reproduction since it increased the number and proportion of pups surviving their first winter. Taken together, the timing of marmot reproduction might evolve via natural selection; however, plastic changes will also be extremely important. Further, future studies on marmots should not operate under the assumption that females reproduce immediately following their emergence.

Scientists’ warning on climate change and insects - G. A. Duffy; L. A. Dyer; J. E. Dell; C. Deacon; G. R. De Snoo; M. Dillon; J. Ellers; Y. Basset; P. Abram; J. Harvey; K. Tougeron; R. Heinen; et al. (Ecological Monographs, 2023)
Abstract Climate warming is considered to be among the most serious of anthropogenic stresses to the environment, because it not only has direct effects on biodiversity, but it also exacerbates the harmful effects of other human‐mediated threats. The associated consequences are potentially severe, particularly in terms of threats to species preservation, as well as in the preservation of an array of ecosystem services provided by biodiversity. Among the most affected groups of animals are insects—central components of many ecosystems—for which climate change has pervasive effects from individuals to communities. In this contribution to the scientists' warning series, we summarize the effect of the gradual global surface temperature increase on insects, in terms of physiology, behavior, phenology, distribution, and species interactions, as well as the effect of increased frequency and duration of extreme events such as hot and cold spells, fires, droughts, and floods on these parameters. We warn that, if no action is taken to better understand and reduce the action of climate change on insects, we will drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems. We discuss perspectives on relevant ways to conserve insects in the face of climate change, and we offer several key recommendations on management approaches that can be adopted, on policies that should be pursued, and on the involvement of the general public in the protection effort.

Biotic and abiotic drivers of plant-pollinator interaction rewiring - Kaysee Arrowsmith (2023)
Biotic and Abiotic Drivers of Plant-Pollinator Interaction Rewiring

Host plant phenology shapes aphid abundance and interactions with ants - M. S. Heschel; Emily H Mooney; M. L. Mullins; C. DiBiase; James H Den Uyl; Alexander Mitchell (Oikos, 2023)

Reactive iron, not fungal community, drives organic carbon oxidation potential in floodplain soils - Christian Dewey; H. R. Naughton; Marco Keiluweit; Bradley Tolar; Scott Fendorf; P. S. Nico (Soil Biology and Biochemistry, 2023)
Wetlands host ∼20% of terrestrial organic carbon and serve as a major sink for atmospheric carbon. Anoxic soils and sediments accrue soil organic carbon (SOC) partly by hampering the activity of extracellular oxidative enzymes that break down phenolic polymers. Upon aeration, fungal-driven oxidative enzymatic depolymerization and microbial respiration of released monomers ensue. Redox-active metals can simultaneously catalyze abiotic nonspecific oxidation of SOC, notable examples including Mn(III) or Fe(II) through Fenton-like, hydrogen peroxide-catalyzed oxidative radical production. However, the extent of reactive metal contributions to biotic and abiotic SOC degradation is not understood in the context of natural environments with diverse redox chemistry. We tested the relative contributions of fungi, Mn(III) and Fe(II) to phenolic substrate (L-DOPA) oxidation in floodplain soils representing a range of transient redox conditions driven by permanent vs. periodic flooding. Phenol oxidative potential was highest in permanently flooded soils with fewer fungal taxa known for observed (per)oxidase activity and instead correlated with HCl-extractable Fe(II), Fe(total) and Fe(II)/Fe(total), suggesting a specific role of Fe(II). Fe(II) additions enhanced phenol oxidative potential in sterilized and non-sterilized soils in the presence of hydrogen peroxide, indicating abiotic Fe-mediated radical chemistry could significantly enhance wetland SOC oxidative depolymerization throughout redox-active floodplain soils. Fungal community composition did not correlate to phenol oxidative potential overall and only more oxic soils adjacent to the river with diverse fungal communities showed declining oxidative potential after sterilization. Mn(III) addition did not significantly enhance phenol oxidative potential across all soils, although it appeared to drive fungal-mediated oxidative potential in the most aerated floodplain soils. Understanding how metals mediate SOC depolymerization as abiotic oxidants or microbially-harnessed enzyme cofactors and substrates in soils under variable hydrologic controls will improve our ability to represent depolymerization in terrestrial carbon models in wetland and other frequently saturated soils.

Two sides of the same wing: ventral scales enhance dorsal wing color in the butterfly Speyeria mormonia - D. I. Speiser; D. R. Chappell; Carol L. Boggs (Journal of Experimental Biology, 2023)
Biological visual signals are often produced by complex interactions between light-absorbing and light-scattering structures, but for many signals, potential interactions between different light-interacting components have yet to be tested. Butterfly wings, for example, are thin enough that their two sides may not be optically isolated. We tested whether ventral wing scales of the Mormon fritillary, Speyeria mormonia, affect the appearance of dorsal orange patches, which are thought to be involved in sexual signaling. Using reflectance spectroscopy, we found that ventral scales, either silvered or non-silvered, make dorsal orange patches significantly brighter, with the silvered scales having the greater effect. Computational modeling indicates that both types of ventral scale enhance the chromatic perceptual signal of dorsal orange patches, with only the silvered scales also enhancing their achromatic perceptual signal. A lack of optical independence between the two sides of the wings of S. mormonia implies that the wing surfaces of butterflies have intertwined signaling functions and evolutionary histories.

Dwindling Groundwater Reserves Will Threaten Mountain Streamflow in a Warmer World - Richard Niswonger; Charuleka Varadharajan; Craig Ulrich; Erica R. Siirila-Woodburn; Kenneth Hurst Williams (Research Square, 2023)
Groundwater storage and release in mountain systems is often ignored compounding uncertainty in how these systems may respond to climate change. To assess the importance of groundwater to mountain streamflow, we combine an extensive data network with a high-resolution, integrated hydrologic model stretching into the deep subsurface for a Colorado River headwater basin. In a warmer climate, increased forest water use reduces recharge, thereby destabilizing groundwater storage such that it cannot recover to historical levels even during simulated wet periods. Groundwater depletion significantly reduces average annual streamflow and forces the basin toward non-perennial conditions during dry water years. Groundwater declines are amplified in high-relief, conifer-dominated catchments. Upscaling model results across the region indicates concentrated risk of groundwater decline in the Colorado Headwater and Gunnison Basins. Research highlights the tight coupling of topography, vegetation and groundwater dynamics and that excluding groundwater response to warming will underestimate future reductions in mountain streamflow.

Group social structure has limited impact on reproductive success in a wild mammal - Conner S. Philson; Daniel T. Blumstein (Behavioral Ecology, 2023)
Abstract The frequency and type of dyadic social interactions individuals partake in has important fitness consequences. Social network analysis is an effective tool to quantify the complexity and consequences of these behaviors on the individual level. Less work has used social networks to quantify the social structure—specific attributes of the pattern of all social interactions in a network—of animal social groups, and its fitness consequences for those individuals who comprise the group. We studied the association between social structure, quantified via five network measures, and annual reproductive success in wild, free-living female yellow-bellied marmots (Marmota flaviventer). We quantified reproductive success in two ways: (1) if an individual successfully weaned a litter and (2) how many pups were weaned. Networks were constructed from 38 968 interactions between 726 unique individuals in 137 social groups across 19 years. Using generalized linear mixed models, we found largely no relationship between either measure of reproductive success and social structure. We found a modest relationship that females residing in more fragmentable social groups (i.e., groups breakable into two or more separate groups of two or more individuals) weaned larger litters. Prior work showed that yellow-bellied marmots residing in more fragmentable groups gained body mass faster—another important fitness correlate. Interestingly, we found no strong relationships between other attributes of social group structure, suggesting that in this facultatively social mammal, the position of individuals within their group, the individual social phenotype, may be more important for fitness than the emergent group social phenotype.

Current and lagged climate affects phenology across diverse taxonomic groups - Alison K. Brody; R. M. Prather; N. C. Underwood; Richard Alexander Smith; Rebecca M. Dalton; Rebecca E. Irwin; Billy Barr; D. H. Van Vuren; Caitlin P. Wells; Howard Whiteman; Brian D. Inouye; David W. Inouye; et al. (Proceedings of the Royal Society B, 2023)
The timing of life events (phenology) can be influenced by climate. Studies from around the world tell us that climate cues and species' responses can vary greatly. If variation in climate effects on phenology is strong within a single ecosystem, climate change could lead to ecological disruption, but detailed data from diverse taxa within a single ecosystem are rare. We collated first sighting and median activity within a high-elevation environment for plants, insects, birds, mammals and an amphibian across 45 years (1975-2020). We related 10 812 phenological events to climate data to determine the relative importance of climate effects on species' phenologies. We demonstrate significant variation in climate-phenology linkage across taxa in a single ecosystem. Both current and prior climate predicted changes in phenology. Taxa responded to some cues similarly, such as snowmelt date and spring temperatures; other cues affected phenology differently. For example, prior summer precipitation had no effect on most plants, delayed first activity of some insects, but advanced activity of the amphibian, some mammals, and birds. Comparing phenological responses of taxa at a single location, we find that important cues often differ among taxa, suggesting that changes to climate may disrupt synchrony of timing among taxa.

Creating Presence and Absence Points - Nicholas E. Young; Daniel Carver; Peder Engelstad (2023)
Abstract The purpose of this chapter is to demonstrate a method to generate your own presence and absence data and distribute those samples using specific ecological characteristics found in remotely sensed imagery. You will see that even when field data is unavailable, you can still digitally sample a landscape and gather information on current or past ecological conditions.

Interannual precipitation controls on soil CO2 fluxes in high elevation conifer and aspen forests - C. M. Boot; barr b; Andrew D. Richardson; Mariah Carbone; Christopher Still; Austin Simonpietri; Max Berkelhammer (Environmental Research Letters, 2023)
Long-term soil CO2 emission measurements are necessary for detecting trends and interannual variability in the terrestrial carbon cycle. Such records are becoming increasingly valuable as ecosystems experience altered environmental conditions associated with climate change. From 2013 to 2021, we continuously measured soil CO2 concentrations in the two dominant high elevation forest types, mixed conifer and aspen, in the upper Colorado River basin. We quantified the soil CO2 flux during the summer months, and found that the mean and total CO2 flux in both forests was related to the prior winter’s snowfall and current summer’s rainfall, with greater sensitivity to rainfall. We observed a decline in surface soil CO2 production, which we attributed to warming and a decrease in amount and frequency of summer rains. Our results demonstrate strong precipitation control on the soil CO2 flux in mountainous regions, a finding which has important implications for carbon cycling under future environmental change.

Single-Well Push–Pull Tracer Test Analyses to Determine Aquifer Reactive Transport Parameters at a Former Uranium Mill Site (Grand Junction, Colorado) - Charles J. Paradis; Paul W. Reimus; Ronald D. Kent; Aaron D. Tigar (Minerals, 2023)
At a former uranium mill site where tailings have been removed, prior work has determined several potential ongoing secondary uranium sources. These include locations with uranium sorbed to organic carbon, uranium in the unsaturated zone, and uranium associated with the presence of gypsum. To better understand uranium mobility controls at the site, four single-well push–pull tests (with a drift phase) were completed with the goal of deriving aquifer flow and contaminant transport parameters for inclusion in a future sitewide reactive transport model. This goes beyond the traditional use of a constant sorption distribution coefficient (Kd) and allows for the evaluation of alternative remedial injection fluids, which can produce variable Kd values. Dispersion was first removed from the resulting data to determine possible reactions before conducting reactive transport simulations. These initial analyses indicated the potential need to include cation exchange, uranium sorption, and gypsum dissolution. A reactive transport model using multiple layers to account for partially penetrating wells was completed using the PHT-USG reactive transport modeling code and calibrated using PEST. The model results quantify the hydraulic conductivity and dispersion parameters using the injected tracer concentrations. Uranium sorption, cation exchange, and gypsum dissolution parameters were quantified by comparing the simulated versus observed geochemistry. All simulations required some cation exchange and calcite equilibrium, and one simulation required gypsum dissolution to improve the model fit for calcium and sulfate. Uranium sorption parameters were not strongly influenced by the other parameter values but were highly influenced by uranium concentrations during the drift phase, with possible kinetic rate limitations. Thus, a future recommendation for such push–pull tests is to collect more geochemical data during the drift phase. The final uranium sorption parameters were within the range of values determined from prior column testing. The flow and transport parameters derived from these single-well push–pull tests will provide initial parameters for any future sitewide reactive transport model.

Sage-Grouse - Jeffrey L. Beck; Kirk W. Davies; David E. Naugle; Adrian P. Monroe; Michael A. Schroeder; Thomas J. Christiansen; Jonathan B. Dinkins (2023)
Abstract In this chapter, we summarize the ecology and conservation issues affecting greater ( Centrocercus urophasianus ) and Gunnison ( C . minimus ) sage-grouse, iconic and obligate species of rangelands in the sagebrush ( Artemisia spp.) biome in western North America. Greater sage-grouse are noted for their ability to migrate, whereas Gunnison sage-grouse localize near leks year-round. Seasonal habitats include breeding habitat where males display at communal leks, nesting habitat composed of dense sagebrush and herbaceous plants to conceal nests, mesic summer habitats where broods are reared, and winter habitat, characterized by access to sagebrush for cover and forage. While two-thirds of sage-grouse habitat occurs on public lands, private land conservation is the focus of national groups including the USDA-NRCS Sage-Grouse Initiative. Sage-grouse are a species of great conservation concern due to population declines associated with loss and fragmentation of more than half of the sagebrush biome. Wildlife and land management agencies have been increasingly proactive in monitoring trends in sage-grouse populations (e.g., lek count index), adapting regulations to reduce harvest on declining populations, and in designing and implementing conservation policies such as core areas to conserve sage-grouse habitats and populations. Much of the remaining sagebrush habitat is threatened by altered fire regimes, invasive annual grasses and noxious weeds, encroaching piñon ( Pinus edulis and monophylla )-juniper ( Juniperus spp.) woodlands, sagebrush conversion, anthropogenic development, and climate change. Several diseases affect sage-grouse, but to date, disease has not been a widespread cause of declines. Proper livestock grazing and limited hunting appear to be sustainable with sage-grouse, whereas improper grazing, increasing free-roaming equid populations, and sagebrush conversion are primary concerns for future conservation. Research has identified additional concerns for sage-grouse including effects from fence collisions, predation from common ravens ( Corvus corax ), and reduced habitat effectiveness resulting from grouse avoidance of anthropogenic infrastructure. There is a need for future research evaluating sage-grouse habitat restoration practices following improper rangeland management, habitat alteration from invasive species and fire, effects on small and isolated populations, and effects from diseases.

Tracking changes in montane butterfly populations through the lens of climate change - N. Shive (2023)

Constraining Bedrock Groundwater Residence Times in a Mountain System With Environmental Tracer Observations and Bayesian Uncertainty Quantification - P. James Dennedy-Frank; William Payton Gardner; Nicholas Thiros; Erica R. Siirila-Woodburn; Kenneth Hurst Williams (Water Resources Research, 2023)
Abstract Groundwater residence time distributions provide fundamental insights on the hydrological processes within watersheds. Yet, observations that can constrain groundwater residence times over broad timescales remain scarce in mountain catchment studies. We use environmental tracers (CFC‐12, SF 6 , 3 H, and 4 He) to investigate groundwater residence times along a hillslope in the East River Watershed, Colorado, USA. We develop a Bayesian inference framework that applies a Markov‐chain Monte Carlo (MCMC) approach to estimate noble gas recharge temperature, elevation, and excess‐air parameters and the resulting environmental tracer concentrations. MCMC is then used to propagate the environmental tracer uncertainties to estimates of groundwater mean residence times inferred with lumped parameter models. All samples contain 3 H, CFC‐12, and SF 6 in addition to terrigenic 4 He, suggesting a mixture of water characterized by modern and premodern residence times. 4 He exponential mean residence times range from hundreds of years at the upslope well to thousands of years at the toe‐slope well assuming average crustal production rates. We find that binary mixing residence time distributions with separate young and old mixing fractions are needed to predict the 4 He, CFC‐12, SF 6 , and 3 H observations, supporting the importance of flow path mixing in this bedrock system. Our findings that the fractured bedrock hosts groundwater with a mixture of residence times ranging from decades to millennia suggest variable recharge dynamics and flow path mixing along the hillslope and highlight the importance of characterizing groundwater systems with observations that are sensitive to transport over a broad range of residence times.

Take only pictures, leave only... Cameras influence marmot vigilance but not perceptions of risk - A. Burkle; K. Uchida; Daniel T. Blumstein (Journal of Zoology, 2023)
Abstract Ecotourism provides an opportunity to experience nature that may promote its conservation. Ecotourists photograph wildlife, and photography plays an important role in focusing public's attention on nature. Although photography is believed to be a low‐impact activity, how the visual stimulus of cameras influences wildlife remains unknown. Since animals are known to fear eyes pointed towards them because of similarity to predator eyes, we predicted that cameras with zoom lens would increase vigilance. Using yellow‐bellied marmots ( Marmota flaviventer ) and adopting a behavioural approach to identify marmots' response to photography, we experimentally quantified proportion of time allocated to vigilance during foraging and flight initiation distance (FID, the distance at which a marmot started to flee from an approaching human) towards humans with and without a camera. We focused on time allocated to vigilance measured in three ways: the proportion of time when marmots moved their head and body towards observers (looking towards observer), the proportion of time when marmots moved their head away from observers (looking away from observer) and the total vigilance (sum of looking towards and away from observer). While a camera was pointed at a marmot, individuals allocated more time to looking towards the observer and less time to looking away from the observer than they did without a camera. However, the total proportion of time allocated to vigilance was not different when marmots were approached by humans with and without a camera. Additionally, whether or not an observer was carrying a camera had no effect on FID. Our results indicated that cameras distracted marmots but did not influence their subsequent risk assessment; marmots may be curious about cameras but were not threatened by them. However, capturing an individual's attention may reduce their ability to look out for predators and thus may increase vulnerability to predation. Regulating photography in locations where predation risk is high or vulnerable species ranges' overlap with humans may be required.

Effects of microclimate, dispersal, species interactions, and environmental stochasticity on demography (2023)
Effects of microclimate, dispersal, species interactions, and environmental stochasticity on demography

Extending the social cohesion hypothesis: Is group cohesion associated with dispersal? - S. Schneidman (2023)
Dispersal is an important decision for an individual to make which may influence individual fitness as well as population viability. Prior work has shown that dispersal decisions can be influenced by an individual’s position in their social network (the social cohesion hypothesis), but the dispersal consequences of group social structure have not been explored. We quantified the affiliative and agonistic social network structure of female yellow-bellied marmots (Marmota flaviventer), a facultatively social ground-dwelling squirrel, where about half of all females disperse, and using mixed-effects models, asked whether group structure was associated with dispersal. We found no support for the hypothesis that affiliative group structure explained any variation in a marmot’s decision to disperse but marmots in groups with less agonistic centralization were less likely to disperse. The former finding may result from cognitive limitations on social knowledge while the later finding might reflect that individuals in less agonistically integrated groups are less likely to be reproductively suppressed. Regardless, these results raise important questions about the limits of social knowledge and suggest the social cohesion hypothesis – more social individuals remain at home – does not scale to the level of the group. Further work is required to determine whether dispersal decisions in obligately social species are influenced by knowledge of their group structure.

River thorium concentrations can record bedrock fracture processes including some triggered by distant seismic events - C. Joe-Wong; Benjamin Gilbert; Sergio Carrero; Bhavna Arora; Patricia Fox; P. S. Nico; Wenming Dong; Kenneth Hurst Williams (Nature Communications, 2023)
Fractures are integral to the hydrology and geochemistry of watersheds, but our understanding of fracture dynamics is very limited because of the challenge of monitoring the subsurface. Here we provide evidence that long-term, high-frequency measurements of the river concentration of the ultra-trace element thorium (Th) can provide a signature of bedrock fracture processes spanning neighboring watersheds in Colorado. River Th concentrations show abrupt (subdaily) excursions and biexponential decay with approximately 1-day and 1-week time constants, concentration patterns that are distinct from all other solutes except beryllium and arsenic. The patterns are uncorrelated with daily precipitation records or seasonal trends in atmospheric deposition. Groundwater Th analyses are consistent with bedrock release and dilution upon mixing with river water. Most Th excursions have no seismic signatures that are detectable 50 km from the site, suggesting the Th concentrations can reveal aseismic fracture or fault events. We find, however, a weak statistical correlation between Th and seismic motion caused by distant earthquakes, possibly the first chemical signature of dynamic earthquake triggering, a phenomenon previously identified only through geophysical methods.

Application of pressure balancing techniques at the West Elk coal mine - Charles Kocsis; Garren Atchley; John Poulos; F. Calizaya; Natanna Nunes; Elizabeth A. Lindgren; Tulio Dias (2023)
Spontaneous combustion is a serious safety hazard in underground coal mines, particularly in mined-out areas (e.g., gob). It is estimated to be the cause of more than 20% of coal mine fires. Pressure balancing is a ventilation technique that can be used to reduce or eliminate the ingress of oxygen to the mine gob (in-gassing), thus reducing the risk of spontaneous combustion. At the same time, pressure balancing can also be used to reduce the risk of methane seeping into the mine ventilation circuits from the gob (out-gassing), due to barometric pressure changes on the surface. Two pressure balancing chambers have been constructed at the West Elk Mine, Colorado, operated by the Mountain Coal Company (MCC): one in a mined-out area, and another close to the active area, near a longwall mine gob. Each chamber is equipped with an isolation stopping, safety doors, a nitrogen injection system, and a set of pressure and environmental monitoring sensors. Several pressure balancing tests for different ventilation conditions have been conducted in these chambers. This study presents a summary of a procedure used to conduct these tests, the results achieved, and the steps taken to reduce the risk of spontaneous combustion.

Lidar and deep learning reveal forest structural controls on snowpack - Ahmad Hojatimalekshah; Josh Enterkine; Nancy F. Glenn; Christopher Hiemstra; T. Trevor Caughlin; Hans‐Peter Marshall; Joel A. Góngora (Frontiers in Ecology and the Environment, 2023)
Forest structure has a strong relationship with abiotic components of the environment. For example, canopy morphology controls snow depth through interception and modifies incoming thermal radiation. In turn, snow water availability affects forest growth, carbon sequestration, and nutrient cycling. We investigated how structural diversity and topography affect snow depth patterns across scales. The study site, Grand Mesa, Colorado, is representative of many areas worldwide where declining snowpack and its consequences for forest ecosystems are increasingly an environmental concern. On the basis of a convolution neural network model ( R 2 of 0.64; root mean squared error of 0.13 m), we found that forest structural and topographic metrics from airborne light detection and ranging (lidar) at fine scales significantly influence snow depth during the accumulation season. Moreover, complex vertically arranged foliage intercepts more snow and results in shallower snow depths below the canopy. Assessing forest structural controls on snow distribution and depth will aid efforts to improve understanding of the ecological and hydrological impacts of changing snow patterns.

The buzz around biodiversity decline: Detecting pollinator shifts using a systematic review - Gillian Bowser; Sarah Whipple (iScience, 2023)
Climate and land use change are two of the largest drivers of worldwide biodiversity loss, but detecting drivers of insect decline is more complex. Online data sources can elucidate such responses while identifying systematic data gaps. Using a systematic review, we found 119 studies that document bumble bee and butterfly responses to climate change. While bee literature was limited, there is high confidence that species are emerging earlier (∼17 days), mismatching with floral resources (100% of studies), and changing range distributions (-25%). More butterfly literature was available but did not yield consistent responses. Evidence shows earlier emergences (∼5 days), decreasing range distributions (-19%), and population shifts amongst generalist (87% increase) versus specialist (65% decrease) groups. We argue that the effect of changing climates on floral emergence, abundance, and distribution may be more significant than the impact of climate change on biodiversity; however, further research is required, particularly within the Southern Hemisphere.

In your stomach or in your nectar? Disentangling the effects of two pollination-related yeasts on bumblebee behavior and foraging - N. Dabagia (2023)
The study of plant-insect interactions and pollination has just begun to scratch the surface of the microbes that inhabit many of the surfaces involved in these interactions. While most microbial studies have focused on the roles of obligate nectar yeasts in mediating pollinator behavior and fitness outcomes in plants, there are entire communities of nectar and pollinator microbes that have been overlooked. Their involvement in these areas is no less important than that of nectar yeasts, but their roles are harder to investigate and quantify. Here, we investigated one such microbe: the bumblebee specialist, Starmerella bombi, which primarily lives in the nests and stomachs of bumblebees but can be dispersed to other bee nests via nectar. By inoculating the species-specific nectar analogue of Corydalis caseana ssp. brandegeei near the Rocky Mountain Biological Laboratory with S.bombi, we tested whether Bombus appositus foragers preferred S. bombi inoculated flowers over sterile control flowers and M. reukaufii inoculated flowers. Furthermore, we assessed whether these insects spend more time at S. bombi-inoculated flowers over sterile flowers and M. reukaufii inoculated flowers. We found that bumblebee foragers showed no preference for either of the focal yeast species when compared to sterile nectar, suggesting that inoculated nectar had no effect on foraging behavior in terms of number of flowers visited, time spent on individual plants, or time spent on individual flowers. Ultimately, this result will contribute to our understanding of how pollinator behavior could be mediated by insect-inhabiting microbes and the role they play in shaping the evolution of floral rewards and potential outcomes to plant fitness.

Agriculture 3.0: Preparing for a Drier Future in the Colorado River Basin - Jane Palmer (Eos, 2023)
Years of drought and climate change are causing water resources to dwindle in the Colorado River Basin. But farmers and scientists are collaborating to learn how to grow crops with less water.

Virus diversity and activity is driven by snowmelt and host dynamics in a high-altitude watershed soil ecosystem - Shi Wang; Simon Roux; Emiley A. Eloe-Fadrosh; Clement Coclet; Ulas Karaoz; Patrick O. Sorensen; Eoin L. Brodie (Microbiome, 2023)
Background Viruses impact nearly all organisms on Earth, including microbial communities and their associated biogeochemical processes. In soils, highly diverse viral communities have been identified, with a global distribu‑ tion seemingly driven by multiple biotic and abiotic factors, especially soil temperature and moisture. However, our current understanding of the stability of soil viral communities across time and their response to strong seasonal changes in environmental parameters remains limited. Here, we investigated the diversity and activity of environmen‑ tal soil DNA and RNA viruses, focusing especially on bacteriophages, across dynamics’ seasonal changes in a snow- dominated mountainous watershed by examining paired metagenomes and metatranscriptomes. Results We identified a large number of DNA and RNA viruses taxonomically divergent from existing environmental viruses, including a significant proportion of fungal RNA viruses, and a large and unsuspected diversity of positive single-stranded RNA phages (Leviviricetes), highlighting the under-characterization of the global soil virosphere. Among these, we were able to distinguish subsets of active DNA and RNA phages that changed across seasons, con‑ sistent with a “seed-bank” viral community structure in which new phage activity, for example, replication and host lysis, is sequentially triggered by changes in environmental conditions. At the population level, we further identified virus-host dynamics matching two existing ecological models: “Kill-The-Winner” which proposes that lytic phages are actively infecting abundant bacteria, and “Piggyback-The-Persistent” which argues that when the host is growing slowly, it is more beneficial to remain in a dormant state. The former was associated with summer months of high and rapid microbial activity, and the latter with winter months of limited and slow host growth. Conclusion Taken together, these results suggest that the high diversity of viruses in soils is likely associated with a broad range of host interaction types each adapted to specific host ecological strategies and environmen‑ tal conditions. As our understanding of how environmental and host factors drive viral activity in soil ecosystems progresses, integrating these viral impacts in complex natural microbiome models will be key to accurately predict ecosystem biogeochemistry.

Contrasting short-and long-term outcomes of pairwise interactions between caddisflies at a hydrologically heterogeneous range margin - I. D. Shepard; S. A. Wissinger; H. S. Greig (Freshwater Biology, 2023)

Historical fire regimes and contemporary fire effects within sagebrush habitats of Gunnison Sage‐grouse - Petar Z. Simic; Ellis Q. Margolis; Jessica R. Young; Manuel K. Lopez (Ecosphere, 2023)
AbstractThe historical role of fire in sagebrush (Artemisia tridentata) landscapes remains poorly understood, yet is important to inform management and conservation of obligate species such as the threatened Gunnison Sage‐grouse (GUSG; Centrocercus minimus). We reconstructed fire histories from tree‐ring fire scars at sagebrush–forest ecotones (10 sites, 111 trees) to better understand the role of fire in sagebrush landscapes of the Upper Gunnison Basin (UGB), Colorado, and how fire may have changed following Euro‐American settlement. We assessed likely influences of historical fire by surveying plant composition and structure at 100 sagebrush sites with and without recent (2001–2020) fires. Tree‐ring fire scars revealed a history of repeated low‐severity fire at sagebrush–forest ecotones until 1892, followed by over a century without fire. Between 1684 and 1892, the mean fire interval (MFI) among sites averaged 49.6 years (ranging from 18.2 to 119 years). Fire over this period occurred synchronously at two or more sites on average every 23.6 years, potentially indicative of spread between sites. Most (70%) of the historical fires burned in the early growing season, consistent with times of strong wind. Recent burns exhibited reductions in sagebrush cover (5% vs. 25% in unburned sites) and concomitant increases in herbaceous cover (55% vs. 40%). These differences declined over time but persisted for at least two decades. Burned sites were dominated by native perennial grasses, forbs, and resprouting shrub species. Historically, such openings may have served as seasonal GUSG habitat. Our results indicate that parts of the UGB sagebrush landscapes were characterized historically by frequent fire and dynamic vegetation mosaics that included open, grassy patches. These findings support the use of prescribed fire to restore and maintain this ecological process and vegetation heterogeneity. However, the contemporary context for fire has changed and now includes substantially reduced, Endangered Species Act (ESA)‐listed GUSG populations, increased risk of non‐native plant invasion, and climate warming. These circumstances highlight new risks, information needs, and opportunities for key knowledge co‐production via management–research partnerships.

Is flight initiation distance associated with longer-term survival in yellow-bellied marmots, Marmota flaviventer? - M. Sanchez; L. Bliard; Conner S. Philson; Daniel T. Blumstein (Animal Behaviour, 2023)
The distance at which animals move away from threats, flight initiation distance (FID), is often used to study antipredator behaviour and risk assessment. Variation in FID is explained by a variety of internal and external biotic and physical factors, including anthropogenic activities. Most prior studies focused on unidentified individuals, so our understanding of the fitness consequences of FID is relatively limited. We asked whether consistent individual differences in variation in flight initiation distance is associated with variation in summer survival and/or winter survival in an individually marked population of yellow-bellied marmots. We found no clear association between flight initiation distance and summer survival or winter survival. This suggests that FID decisions, while demonstrably optimizing current survival, may not have longer-term fitness consequences. Our results may be explained by the relatively modest repeatability of FID or it may have emerged from our attempt to explain longer-term measures of fitness. Future studies of the fitness consequences of personality traits should pay particular attention to the time interval between measuring the individuality of a trait and examining its fitness consequences.

Investigating the Effect of Drought on Floral Traits Mediating Pollinator Interactions - Z. Zarling (2023)
Understanding the effects of water stress on flowering plants is crucial for ecosystem sustainability. Changing water availability due to climate shifts and persistent drought conditions have significant implications for the reproduction and survival of subalpine plants and their pollinators. This paper addressed two key questions: (1) Do changes in soil moisture levels have an effect on floral height and display size? (2) What is the relationship between floral traits and pollinator visitation? Field data was collected from three subalpine meadows in Gunnison County, Colorado, including measurements of floral traits, soil moisture, and pollinator visitation spanning three years. Our research team measured the floral display size, height, and abundance of two focal species: Linum lewisii, and Potentilla pulcherrima. The outcomes revealed a series of correlations: higher soil moisture was associated with taller plants but diminished displays. Pollinator visitation showed no significant correlations with floral traits.

How beaver pond age affects aquatic invertebrates - J. Rivera (2023)
Beavers are ecological engineers, benefitting the aquatic ecosystems with their dams and ponds. The beaver ponds change over time; beaver ponds of different ages will have different characteristics. These differences will influence what types of aquatic invertebrates will inhabit these ponds. Understanding these different successional stages will help us understand more about the beavers’ role in the ecosystem. We surveyed three newer beaver ponds and four older beaver ponds to assess the aquatic invertebrate community composition and taxa richness. The newer beaver ponds had an average of 18 taxa, whereas the older beaver ponds had an average of 28.25 taxa. The community composition between newer and older ponds was significantly different, due to some species that were unique or abundant for each pond age group. The habitat in the newer ponds is a type of middle ground between wetland and stream habitat. This could mean that few wetland and stream invertebrates can colonize there. The presence of trout in the newer ponds could also contribute to the low number of taxa. Learning more about the biodiversity associated with successional stages of beaver ponds can inform evaluation criteria for restoration using beaver and improve our understanding of beavers’ role in the ecosystem.

A tyrannosaurid pedal ungual from the Williams Fork Formation (Campanian) of Colorado and its implications for the biogeography of Laramidian dinosaurs - Chan-Gyu Yun (Acta Geologica Polonica, 2023)
A right theropod pedal ungual phalanx II-3 from the Campanian Williams Fork Formation of northwestern Colorado is described, and a combination of features, including the large size, tapering distal tip, robust and stout overall form, triangular cross-section, and a relatively flat ventral surface allows a confident referral to Tyrannosauridae Osborn, 1906. Although this specimen was found in a relatively southern state, the proximal articular surface of this ungual is similar to that of Gorgosaurus libratus Lambe, 1914, a taxon found in the northern state, Alberta. Although based on limited evidence, this may suggest that the range of tyrannosaurids considered endemic to the north of Laramidia extended farther south than previously thought.

Are juvenile female golden mantle ground squirrels dispersing from their natal burrow due to high-stress levels? - K. Carrera (2023)
Many mammals disperse from the area they were born in. Dispersal is done to avoid inbreeding, resources, and mate competition. Dispersal in mammals tends to be male-biased as juvenile males are the ones that often leave their natal burrow, and females do not. The cost of dispersal is expensive as mammals would need to fight for new territory and compete for resources. Females, on the other hand, either stay in their natal burrows or disperse. Females are either kicked out by their mothers or dispersed voluntarily. Many factors contribute to female juvenile dispersal. For instance, avoiding kin competition, resource, and inbreeding. There is also the physiology associated with dispersal in juveniles. Glucocorticoids help regulate energy balances in animals. And cortisol, a stress hormone that could determine if a female juvenile will disperse away from stressful conditions. Stress could also be associated with weight gain as bigger juvenile females tend to disperse while smaller females did not. In this study, we will look at stress's effects on Golden mantle ground squirrels. It will be conducted in the Rocky Mountain Biological Laboratory, located in the East River valley of Gunnison, Colorado.

Effects of a caddisfly range shift on competition and facilitation in high elevation ponds - A. Ardito (2023)
As temperatures warm, the climate crisis is having a significant influence on species all across the world and altering their distributions. Colorado's high elevation ponds have recently observed a species range shift, traveling to higher altitudes than they have previously inhabited. The Mexican Cut Nature Preserve near the Rocky Mountain Biological Laboratory in Gothic, CO, is home to a prominent caddisfly Limnephilus externus, but recently a new range-shifting species, Nemotaulius hostilis, has appeared. Caddisflies play an essential role in nutrient cycling and putting energy back into the food web. The range-shifting species is known to excrete high rates of phosphorus (P), and could potentially facilitate the growth of a nutrient dense food source for the resident species. However, the range-shifting species and the resident species have differing life histories and emergence patterns that could increase interspecific competition between the two caddisfly populations. This study aims to understand the ecological impacts that the range-shifting species Nemotaulius hostilis is having on facilitating resources or competing for resources with the resident species Limnephilus externus.

Daily roadkill monitoring and long-term population census reveal female-biased mortality for a small mammal along a wildland-urban interface - K. Burgstahler; A. C. Collins; J. Isidro; J. R. Aliperti; D. H. Van Vuren; Caitlin P. Wells (Biological Conservation, 2023)

Antibody development to identify components of IIS and mTOR signaling pathways in lepidopteran species, a set of non-model insects - Augustus Armstrong; Carol L. Boggs (microPublication Biology, 2023)
Nutritional stress impacts many insect species that have differing reproductive strategies and life histories, yet it is unclear how nutrient-sensing signaling pathways mediate tissue-specific responses to changes in dietary input. In Drosophila melanogaster, insulin/insulin-like growth factor (IIS) and mTOR-mediated signaling within adipocytes regulates oogenesis. To facilitate comparative study of nutrient-sensing pathway activity in the fat body, we developed antibodies to assess IIS (anti-FOXO) and mTOR signaling (anti-TOR) across three µP microPublication Biology Submit a microPublication nymphalid species (Lepidoptera). By optimizing whole-mount fat body immunostaining, we find FOXO nuclear enrichment in adult adipocytes, like that observed in Drosophila. Additionally, we show a previously uncharacterized TOR localization pattern in the fat body. µP microPublication Biology Submit a microPublication

Using GIS techniques to test a model of the coexistence of the golden-mantled ground squirrel, Callospermopholis lateralis, and the least chipmunk, Tamias minimus (2023)
Predator-prey interactions extend beyond direct predation and can influence prey behavior and habitat use. This “ecology of fear” has been studied in a wide variety of taxa, and differences in perceived predation risk have been demonstrated to impact species coexistence. Previous research (Smith 1991, Baas 2011) on the golden-mantled ground squirrel (Callospermophilus lateralis) and the least chipmunk (Tamias minimus) has indicated that these species have differing foraging efficiencies at different distances from cover; T. minimus is more efficient close to cover, and does not venture too far from safety, while C. lateralis is able to exploit “riskier” habitat in the center of a meadow. The aim of this study was 1) to test the continued coexistence of C. lateralis and T. minimus to determine if their patterns of meadow usage are stable and 2) to use geographic information systems (GIS) to refine the methodologies used by Smith (1991) and Baas (2011). Raster analysis in GIS was utilized to locate meadows with appropriate habitat and determine the distance from cover and area of each meadow. Meadows were observed visually and with camera traps to record the presence of one or both sciurid species. Data was analyzed using logistic regression and it was found that both distance from cover and area of a meadow contribute to species composition. Results are consistent with past studies, indicating that the coexistence of these two species is stable. This research provides further evidence that the non-consumptive effects of predators promote species diversity.

Elevation Does Not Predict Density Dependent Population Dynamics in Valeriana edulis - B. E. Davis (2023)
Density dependence—the impact of neighbors on the survival, growth, or reproduction of individuals—strongly impacts the size and dynamics of populations. However, it is unknown how the effects of density dependence vary across species ranges, which will be integral knowledge in the face of climate change and shifting populations. We sought to determine whether density dependence varies systematically across a species elevation range in the long-lived perennial plant Valeriana edulis (valerian). We assessed density dependence three ways across the species elevation range. First, we measured natural population density. Second, we quantified the impact of neighbor density on individuals survival, growth, flowering, and seed production. Third, we combined the measures of density dependent individual performance into a demographic model and projected the population’s carrying capacity. There was no significant relationship between observed population density and elevation. However, density dependence impacted multiple parts of the plant life cycle: size-specific survival and flowering probabilities of individual plants decreased with increasing numbers of neighbors. Finally, integrating the impacts of density across the full life cycle revealed that there was no significant relationship between elevation and model-projected carrying capacity. Taken together, these results suggest that density dependence has idiosyncratic effects on population dynamics across a species’ range. Davis 3

Evidence for a single, ancient origin of a genus-wide alternative life history strategy - J. J. Hanly; W. B. Watt; A. Y. Kawahara; V. Ficarrotta; Andrew P. Martin; A. H. Porter; C. W. Wheat; A. Chichvarkhin; K. Tunstrom; S. D. Schoville; A. D. Warren; A. Woronik; et al. (Science Advances, 2023)

Plant Bioassay Testing Soil Quality Following Carrion Insect Activity - B. Guijosa (2023)
The decomposition of animal carrion, particularly small animals that are used as a breeding resource for carrion insects, is little studied but is likely to be a major component of nutrient cycling in many ecosystems. This project focuses on how carrion insects affect small vertebrate carrion decomposition and what nutrients are put back into the soil. My research question is: How nutritious does soil become after carrion insect activity, and how can this be observed? Using three different types of carrion insects (two species of beetles and the common flies found here at RMBL), and carrion sources I plan to collect impacted soil and allow small vertebrate carrion decomposition and carrion insect activity to occur on the soil. I aim to compare how carcass visitation and consumption by three different types of carrion insects affects soil nutrients and will measure this nutrient addition through a plant growth bioassay. The findings may be applied to techniques for restoring impacted soils.

Evolvability and trait function predict phenotypic divergence of plant populations - T. F. Hansen; G. M. Walter; J. Agren; C. G. Eckert; G. H. Bolstad; O. H. Opedal; Asa Lankinen; C. M. Caruso; S. Andersson; W. S. Armbruster; A. Holstad; L. F. Delph; et al. (Proceedings of the National Academy of Sciences, 2023)
Understanding the causes and limits of population divergence in phenotypic traits is a fundamental aim of evolutionary biology, with the potential to yield predictions of adaptation to environmental change. Reciprocal transplant experiments and the evaluation of optimality models suggest that local adaptation is common but not universal, and some studies suggest that trait divergence is highly constrained by genetic variances and covariances of complex phenotypes. We analyze a large database of population divergence in plants and evaluate whether evolutionary divergence scales positively with standing genetic variation within populations (evolvability), as expected if genetic constraints are evolutionarily important. We further evaluate differences in divergence and evolvability-divergence relationships between reproductive and vegetative traits and between selfing, mixed-mating, and outcrossing species, as these factors are expected to influence both patterns of selection and evolutionary potentials. Evolutionary divergence scaled positively with evolvability. Furthermore, trait divergence was greater for vegetative traits than for floral (reproductive) traits, but largely independent of the mating system. Jointly, these factors explained ~40% of the variance in evolutionary divergence. The consistency of the evolvability-divergence relationships across diverse species suggests substantial predictability of trait divergence. The results are also consistent with genetic constraints playing a role in evolutionary divergence.

Differences in individual flowering time change pollen limitation and seed set in three montane wildflowers - A. Schiffer; C. N. Morozumi (American Journal of Botany, 2023)
Our study shows that variation in individual phenology affects fecundity in three phenologically distinct montane species, and that pollen limitation may be more influential than conspecific density. Our results suggest that individual-level changes in phenology are important to consider for understanding plant reproductive success.

Optimal reproductive strategy in yellow-bellied marmots: Unveiling the consequences of age at first reproduction on survival and lifetime reproductive success (2023)
When to reproduce for the first time is a key question in evolutionary ecology.

Efficacy and Uses of PIT Tag Telemetry in Salamanders From the Western USA: , Aneides vagrans , Ensatina eschscholtzii , and Ambystoma mavortium - S. B. Marks; J. Campbell-Spickler; C. E. Brown; J. O. Reiss; Howard Whiteman (Herpetological Conservation and Biology, 2022)

Environmental and Genetic Effects of Elevation on Plant Defense - M. Sherwood (2022)
Plant communities are shaped by their interactions with biotic and abiotic factors in their environment, including herbivores. In response to pressures from herbivores, plants develop a variety of physical and chemical defenses to protect themselves. The investment that plants make in these defenses varies with the environment. Using fully reciprocal turf transplants at three different elevations and a variety of focal plant species, we tested patterns of plant defense against herbivory along elevational gradients and examined whether any intra-specific variation in plant defense is due to genetic variation among populations and/or are changed by the environment of the plant. After collecting leaves in the field and conducting grasshopper feeding bioassays, our experiment did not find any significant effect of treatments in either the environmental or the genetic tests. This result contradicts previous work done at RMBL and in other study systems. One possible explanation for this is that our elevational gradient was not large enough to see noticeable differences in plant defense. Another possible explanation is that it was a very low year for grasshopper abundance and it’s possible they had a disease or parasite that was causing changes to their eating patterns. Further experiments are required to draw conclusions about genetic and environmental effects on plant defense.

Modeling Spatial Distribution of Snow Water Equivalent by Combining Meteorological and Satellite Data with Lidar Maps - Ilhan Özgen-Xian; J. B. Brown; Utkarsh Mital; Carl I. Steefel; Dipankar Dwivedi (Artificial Intelligence for the Earth Systems, 2022)
Abstract An accurate characterization of the water content of snowpack, or snow water equivalent (SWE), is necessary to quantify water availability and constrain hydrologic and land surface models. Recently, airborne observations (e.g., lidar) have emerged as a promising method to accurately quantify SWE at high resolutions (scales of ∼100 m and finer). However, the frequency of these observations is very low, typically once or twice per season in the Rocky Mountains of Colorado. Here, we present a machine learning framework that is based on random forests to model temporally sparse lidar-derived SWE, enabling estimation of SWE at unmapped time points. We approximated the physical processes governing snow accumulation and melt as well as snow characteristics by obtaining 15 different variables from gridded estimates of precipitation, temperature, surface reflectance, elevation, and canopy. Results showed that, in the Rocky Mountains of Colorado, our framework is capable of modeling SWE with a higher accuracy when compared with estimates generated by the Snow Data Assimilation System (SNODAS). The mean value of the coefficient of determination R 2 using our approach was 0.57, and the root-mean-square error (RMSE) was 13 cm, which was a significant improvement over SNODAS (mean R 2 = 0.13; RMSE = 20 cm). We explored the relative importance of the input variables and observed that, at the spatial resolution of 800 m, meteorological variables are more important drivers of predictive accuracy than surface variables that characterize the properties of snow on the ground. This research provides a framework to expand the applicability of lidar-derived SWE to unmapped time points. Significance Statement Snowpack is the main source of freshwater for close to 2 billion people globally and needs to be estimated accurately. Mountainous snowpack is highly variable and is challenging to quantify. Recently, lidar technology has been employed to observe snow in great detail, but it is costly and can only be used sparingly. To counter that, we use machine learning to estimate snowpack when lidar data are not available. We approximate the processes that govern snowpack by incorporating meteorological and satellite data. We found that variables associated with precipitation and temperature have more predictive power than variables that characterize snowpack properties. Our work helps to improve snowpack estimation, which is critical for sustainable management of water resources.

Effects of Experimental Water Addition on Floral Nectar Traits - M. Ferguson (2022)
Plant-pollinator interactions rely on the exchange of nectar and pollen for pollination services. Nectar traits can be influenced by changes in abiotic factors such as water availability, and such variation may in turn influence interactions with pollinators. This experiment investigated how the nectar traits in subalpine plant species responded to increased water availability compared to control conditions. We collected data on three components of floral nectar traits: nectar volume (µl), nectar sugar concentration (mg/µl), and total nectar sugar (mg) for four different wildflower species: Delphinium nuttallianum (Ranunculaceae), Delphinium barbeyi (Ranunculaceae), Eremegone congesta (Caryophyllaceae), and Erigeron speciosus (Asteraceae). Delphinium nuttalianum, Delphinium barbeyi, and Erigeron speciosus all showed no pattern between the control and water addition plots, suggesting these species can maintain nectar traits across variable water availability conditions. Erigeron speciosus showed a marginal increase in sugar content, which was not previously predicted in our hypotheses. We found that Eremegone congesta was the most sensitive to changes in water availability, with a significant decrease in nectar volume and sugar content due to water addition treatment.

Downscaled hyper-resolution (400 m) gridded datasets of daily precipitation and temperature (2008-2019) for East Taylor subbasin (western United States) - J. B. Brown; Utkarsh Mital; Carl I. Steefel; Dipankar Dwivedi (Earth System Science Data Discussions, 2022)
Abstract. High resolution gridded datasets of meteorological variables are needed in order to resolve fine-scale hydrological gradients in complex mountainous terrain. Across the United States, the highest available spatial resolution of gridded datasets of daily meteorological records is approximately 800 m. This work presents gridded datasets of daily precipitation and mean temperature for the East-Taylor subbasin (in western United States) covering a 12-year period (2008–2019) at a high spatial resolution (400 m). The datasets are generated using a downscaling framework that uses data-driven models to learn relationships between climate variables and topography. We observe that downscaled datasets of precipitation and mean temperature exhibit smoother spatial gradients compared to their coarser counterparts. Additionally, we also observe that when downscaled datasets are reaggregated to the original resolution (800 m), the mean residual error is almost zero, ensuring spatial consistency with the original data. Furthermore, the downscaled datasets are observed to be linearly related to elevation, which is consistent with the methodology underlying the original 800 m product. Finally, we validate the spatial patterns exhibited by downscaled datasets via an example use case that models lidar-derived estimates of snowpack. The presented dataset constitutes a valuable resource to resolve fine-sale hydrological gradients in the mountainous terrain of the East-Taylor subbasin, which is an important study area in the context of water security for southwestern United States and Mexico. The dataset is publicly available at https://doi.org/10.15485/1822259 (Mital et al., 2021).

Earlier snow melt and reduced summer precipitation alter floral traits important to pollination - Li Xinyu; Heather M. Briggs; R. G. Dickson; J. M. Powers; Diane R. Campbell (Global Change Biology, 2022)

Maternal survival costs in an asocial mammal - K. P. Huyvaert; R. Kanaziz; L. M. Aubry; Caitlin P. Wells; D. H. Van Vuren (Ecology and Evolution, 2022)
Maternal characteristics, social dynamics, and environmental factors can all influence reproduction and survival and shape trade-offs that might arise between these components of fitness. Short-lived mammals like the golden-mantled ground squirrel (GMGS; Callospermophilus lateralis) tend to maximize effort toward current reproduction at the expense of survival but may be complicated by other aspects of the species' life history and environment. Here, we use 25 years of data (1995-2020) collected from a population of GMGS at the Rocky Mountain Biological Research Laboratory in Gothic, Colorado, to test the effect of several maternal characteristics (e.g., age, experience, and timing of litter emergence), social context (e.g., litter sex ratio and kin density), and environmental context (e.g., date of bare ground and length of vegetative growing season) on survival of reproductive female GMGS using Cox proportional hazard models. Our results indicated that social dynamics (i.e., density) and environmental conditions (i.e., standardized first day of permanent snow cover and length of growing season) explained significant variation in annual maternal survival, while maternal characteristics did not. A higher density of related breeding females and the total number of females (both related and unrelated to the focal mother) were associated with an increase in the mortality hazard. A later standardized date of the first day of permanent snow cover and a shorter growing season both reduced the maternal mortality hazard. Together, our results suggest that factors extrinsic to the squirrels affect maternal survival and thus may also influence local population growth and dynamics in GMGS and other short-lived, territorial mammal species.

Bumble bee queen plasticity and social regulation of traits (2022)
Studies on the physiological states of wild-caught organisms are essential to uncovering the links between ecological and physiological processes. Bumble bee queens emerge from overwintering in the spring. At this time, queens develop their ovaries and search for a nest site in which to start a colony. Whether these two processes, ovary development and nest-searching, interact with or influence one another remains an unresolved question in behavioral physiology. We explored the hypothesis that ovary development and nest-searching might be mechanistically connected, by testing whether (1) ovary development precedes nest-searching behavior; (2) nest occupation precedes ovary development; or (3) ovary development and nest-searching occur independently, in bumble bee (Bombus vosnesenskii) queens. We collected queens either nest-searching (and thus prior to occupying a nest) or pollen-collecting (and thus provisioning an occupied nest) and measured their degree of ovary activation. We further screened these queens for parasites or other symbionts, 7 to identify additional factors that may impact their reproductive success at this time. We found that queens searched for and occupied nests at all stages of ovary development, indicating that these processes occur independently in this system. Nest-searching queens were more likely to have substantial mite loads than pollen-collecting queens, who had already located and occupied a nest. However, mite loads did not significantly predict ovary developmental status. Collectively, our work shows that nesting status and symbionts alone are insufficient to explain the variation in spring bumble bee queen ovary development. We propose that ovary development and nest-searching occur opportunistically, which may enable queens to begin laying eggs earlier in the season than if these processes occurred in discrete succession.

Effects of Temperature on Voltinism in Subalpine Potter Wasps (Vespidae: Eumeninae) - A. Zuber (2022)
Voltinism, the number of generations produced per year, is under both genetic and environmental control in insects. The rapid temperature increases associated with climate change could distort the information insects are obtaining from environmental cues and possibly alter the number of generations produced per year. This summer I investigated the effects of temperature on voltinism in potter wasps (Vespidae: Eumeninae). Previous observations suggest that some eumenines around RMBL are bivoltine, while most are univoltine. I focused on whether variables such as temperature, time of year at which an egg was laid, source population, or taxon may be responsible for this variation. I observed individual wasps building nests at multiple study sites varying in elevation, collected completed nests from said sites, isolated eggs or larvae from these nests and subjected them to one of two temperature conditions (boxes exposed to warm or cool temperatures) to observe the effects on development and time until an individual began cocooning. Warm boxes experienced average maximum daily temperatures 4-18°C warmer than cooler boxes. A generalized linear mixed model showed that while site of origin, date laid and box pair had no effect on rates of cocooning, final age, temperature treatment, and source nest did. These results demonstrate how environmental factors influence wasp development. While genetic effects may factor in as well, more work must be done to conclude that the effect of source nest isn't merely a result of additional environmental factors such as those experienced in early life (before the start of experimental treatments) or maternal effects. These results add to our understanding of the broader consequences of climatic warming for insect life-history strategies and potential changes in eumenine wasp populations. 1

Remote sensing of cytotype and its consequences for canopy damage in quaking aspen - K. E. Mock; Suzanne B. Marchetti; J. A. Walton; Philip G. Brodrick; K. Dana Chadwick; Benjamin Blonder; Ian K Breckheimer (Global Change Biology, 2022)
AbstractMapping geographic mosaics of genetic variation and their consequences via genotype x environment interactions at large extents and high resolution has been limited by the scalability of DNA sequencing. Here, we address this challenge for cytotype (chromosome copy number) variation in quaking aspen, a drought‐impacted foundation tree species. We integrate airborne imaging spectroscopy data with ground‐based DNA sequencing data and canopy damage data in 391 km2 of southwestern Colorado. We show that (1) aspen cover and cytotype can be remotely sensed at 1 m spatial resolution, (2) the geographic mosaic of cytotypes is heterogeneous and interdigitated, (3) triploids have higher leaf nitrogen, canopy water content, and carbon isotope shifts (δ13C) than diploids, and (4) canopy damage varies among cytotypes and depends on interactions with topography, canopy height, and trait variables. Triploids are at higher risk in hotter and drier conditions.

Rates of Cannibalism in Asynarchus Nigriculus based on Sedge Nutrient Content - M. Saab (2022)
Understanding the dynamic interactions between aquatic invertebrates is critical in forming an accurate illustration of mountain stream ecology. Aquatic detritivores, such as A. Nigriculus, form the majority of the biomass in mountain ponds and rivers around Colorado, as they are usually the primary consumers of aquatic detritus. However, certain species of caddisflies in these sub-alpine ponds, such as Asynarchus nigriculus larvae, feed on other caddisflies and cannibalize one another as well. This is probably a supplementation for caddisfly larvae to grow as rapidly as they do in these temporary ponds up in the Mexican Cut, at around 11500 feet in subalpine elevation, which is notorious for having a nutritionally poor environment (Fig. 4). In our study, we manipulate the number of nutrients in the water, enhancing their diet, to observe if the additional nutrients cause a shift in A. nigriculus larvae feeding behavior. The main nutrients we are studying, and which we are supplementing, are nitrogen and phosphorus since these are what have been studied in previous similar experiments regarding Asynarchus nigriculus. Through our experiment, we found the average body size, behavior, and mortality of caddisfly larvae in the function of the treatment ( additional Phosphorus, additional Nitrogen, additional Phosphorus, and Nitrogen, or control) they were receiving. It is difficult to predict mortality and behavior between each of the treatments, or if the sedge detritus (or the microorganisms inhabiting their surface) have taken up the nutrients at all.

The Impacts of Changing Temperature on Plant Water Use - V. Lenis (2022)
The movement of water through a plant’s parts, out its stomata, and into the atmosphere begins with moisture available in the soil. Soil water availability is determined by rates of evaporation from the Earth’s surface, which increases with temperature. Alteration of water content determines the soil’s water potential, the tendency of water to move from one area to another due to physical pressure forces. The means by which plants utilize and transport water occurs along a water potential gradient in a soil-plant-atmosphere-continuum. Water eventually exits the plant via transpiration when the leaves’ stomata open to release vapor and receive carbon dioxide. Water availability is critical for plants’ physiological processes and is determined by a mixture of environmental abiotic factors. Thus, the plots in the Reciprocal Transplant Experiment have been moved to different sites along the Washington Gulch elevation gradient to experience different warming or cooling temperatures. Water potential patterns are mainly studied in woody plant species and the water potential of herbaceous species is heavily understudied. My observational study focused on five different herbaceous species at these turf sites. At each site and their experimental treatment plots, I recorded weather observations, measured the soil moisture of the turfs, and water potential of the individual plants. At the intermediate site that had both cooled and warmed plots, I measured leaf gas exchange for the plant individuals which accounts for their stomatal conductance rates. I hypothesized that plants do not have an acclimated response and rather, as warming temperatures increase, soil becomes drier which leads to more negative water potential values and lower transpiration rates: the inverse for cooling temperatures. Results found that, although water potential did vary along the elevation gradient in the hypothesized way, soil moisture was highest at the lowest elevation site and lowest at the highest site. Moreover, along the warming and cooling treatments, there was no significant difference in plant water stress: there was no significant difference in stomatal conductance either. These outcomes suggest inter-annual variability in water availability, the plants have an ability to converge with their surroundings, and a complex model that accounts for climatic conditions should occur in the future.

Early-life trade-offs in golden-mantled ground squirrel sociality and growth rate - R. Hart (2022)
The golden-mantled ground squirrel (Callospermophilus lateralis) was first classified as an asocial sciurid in 1983, and little follow-up research has effectively challenged this notion since the early literature. The only recognized social behavior in the species has been documented between young littermates, between a mother and her litter, and occasionally across unrelated or partially related litters of overlapping home ranges. However, little research has been conducted on the potential impacts of pup sociality on early life fitness. In this study, the early-life behaviors of golden-mantled ground squirrels were observed in eight litters in the Gothic Townsite of the Rocky Mountain Biological Laboratory during the first two weeks after pup emergence when sociality is at a peak. A multiple linear regression model was used to compare the relationship between time spent socializing and pup growth rate. This model also accounted for the additive effect of pup age on growth rate and the potential interaction between sociality and litter size (i.e., having more littermates may impact sociality). While the final study model was just shy of significant (p= 0.0565), the estimate value of -2.127 showed a consistent, meaningful negative effect (-2.127 ± std. =1.030 = -1.097 or -3.157). Unfortunately, due to high predation rates, roadkill events, and natural loss of litters, the low sample size limits conclusions we can draw from these results. Patterns of early-life sociality in an asocial species such as the golden-mantled ground squirrel are important to understand as they may play an important role in juvenile fitness or later life success. Key words: Golden-mantled ground squirrel (Callospermophilus lateralis), social behavior, growth rates, juvenile fitness, early life trade-offs

Effects of Floral Abundance, Pollinator Interactions, and Floral Morphology on Stigmatic Pollen Deposition - M. Cathcart (2022)
Pollination is a major driver of plant reproductive success and facilitates the growth of many of our major crops and is a foundation to the diversity of many ecosystems. Understanding the ecology of pollination will help preserve this important ecosystem service and predict the changes that will come with climate change. During pollination a pollinator transfers pollen to the stigma of a plant and the plant’s reproductive success is determined by the receipt of conspecific pollen. Many factors can determine the ratio of conspecific to heterospecific pollen that is deposited on the stigma of an individual plant. The available pollinator community and their level of specialization, flower morphology, and the composition of the floral community all can interact in complex ways to influence the composition of pollen deposition. I hypothesize that in subalpine meadows of the Rocky Mountains the most significant driver of conspecific pollen deposition is relative floral abundance. My results show that both relative interaction abundance and relative floral abundance had insignificant effects on the deposition of conspecific pollen and that flower morphology could be the strongest driver.

Evolution of foraging traits in hummingbirds - N. M. Alexandre (2022)

Assessing the Impact that the Keystone Species, the Red Naped Sapsucker ( Sphyrapicus nuchalis ), has on the Community of Species in the East River - V. Cruz (2022)
The Red naped sapsucker (Sphyrapicus nuchalis) is considered a double keystone species. The first method is by creating nesting cavities that other species are unable to replicate, so when the cavities are abandoned, that community of species is able to utilize the space for their own reproductive site. The second method is by creating sap well sites that a different select group of species makes use of by visiting the wells and robbing the sap that is exuded. Here in the East River Valley, I reassesed the claim of S. nuchalis being a double keystone species by performing an observational study (in-person and using motion-activated cameras) of the visitors to the sap wells. I identified eight species (birds, insects, rodents) that fed from the sap wells, measured frequency of visits, quality of the sap, sapsucker behaviors. I detected a reduction in population numbers of sapsuckers and warblers but not of hummingbirds using 20 years of data from Rocky Mountain Biological Laboratory Breeding Bird survey. I compared my results to Gretchen Daily and Paul Ehrlich’s study conducted in 1987 and reevaluated the claim that Sphyrapicus nuchalis is a double keystone species. Low visitation by saprobbers suggests that wells are only used opportunistically and sap feeders are not dependent on this resource to the extent that the sapsuckers are key to their abundance.

Intraspecific Variation in Responses of a Montane Grass, Festuca thurberi , to Simulated Biological Invasion - E. A. Cousins; K. A. Stinson; A. N. Trautwig (Frontiers in Forests and Global Change, 2022)

Dynamics of male inconstancy in Valeriana edulis in the abiotic and mating environment - D. Pham (2022)
This study investigated inconstancy in the sex-expression of male flowers across populations of Edible Valerian (Valeriana edulis) as well as potential drivers of its variation. Though Valeriana edulis is dioecious (individuals typically have separate sexes), plants showing dominant male sex-expression may also produce female reproductive structures (stigmas). As such, we aimed to (1) characterize variation in male inconstancy in V. edulis populations and explore the influence of the (2) abiotic environment and (3) mating environment on the distribution of inconstant sex expression in what is considered a dioecious system. To address these goals, we conducted flower surveys in multiple populations to determine the degree, frequency, and variation in expression of inconstancy (i.e. how inconstancy varies between individuals or flowers). We also tested potential abiotic drivers of inconstancy using remotely sensed datasets for growing degree days as a proxy for temperature and snowmelt date to represent soil moisture. Finally, we obtained operational sex ratios (proportion of flowering individuals that are primarily male-expressing) through demographic surveys of the populations to examine its effect on male inconstancy. These results have implications for potentially reclassifying Valeriana edulis as a dioecious species, exploring the limitations of binary thinking, and gaining a better understanding of how differential effects of the environment on individuals may in turn affect population biodiversity, performance, and persistence. Key words: Dioecy, subdioecy, sex ratios, labile sex-expression, binary thinking, climate change, elevation gradient, Valeriana edulis

Effects of clumping of Delphinium barbeyi on pollination - J. Troper (2022)
The spatial clustering of plants occurs for a variety of reasons, including the evolution of concentrated floral displays to attract more pollination. Within clusters, traits that attract pollinators may differ from non-cluster conditions– such as increasing floral display size andscent, which can cause an increase in pollinator visitation, which in turn increase the reproductive success of plants. In this study I focused on plant neighborhood density, one potential driver of pollination, to further understand pollination systems in times of change and challenge to these structures. More specifically, I examined the question of whether higher density clumping of Delphinium barbeyi increases pollination, and at what spatial scales this effect occurs. I used drone remote sensing, and spatial analysis to choose research sites and measure global densities of D. barbeyi, and collected additional data on local density with manual measurements. In order to measure pollination, I used pollen count, determined through pollen smashing. I found that the most significant global density that impacts the pollination of D. barbeyi is at a 40 meter to 70 meter scale, when comparing global scales of 20 meters to 80 meters. The relationship between pollen count and global density along with pollen count and local density were both found to be significant across scales of 20 meters to 80 meters. In addition, after adding plant fitness to the regression, the relationship across all scales remained significant.

The Effect of Climate Change on Soil Organic Carbon over an Elevational Gradient - T. Issa (2022)
Climate change will increasingly impact ecosystem functioning due to shifts in species distributions as they seek their optimal climatic conditions. Plants rely on phenotypic plasticity of leaf traits to tolerate a change in their climate. Plant leaf traits also affect the carbon cycle of the local area, which may impact the carbon sequestration of the soils. For this project, I measured soil organic carbon over time using space-for-time substitution to study plant communities along an elevational gradient. I collected soil moisture, carbon, and efflux and, in addition, conducted a community survey of the plant species. Both soil carbon and soil moisture significantly increase across an elevational gradient. Additionally, soil carbon is best explained through a combination of soil moisture and biomaterial weight. As soil organic carbon is vulnerable to environmental changes, monitoring soil organic carbon is necessary to determine if there is a loss of carbon sequestration in the area, which can accelerate climate change.

The effects of spatial and temporal resolution of gridded meteorological forcing on watershed hydrological responses - E. T. Coon; Pin Shuai; X. Chen; Utkarsh Mital; Dipankar Dwivedi (Hydrology and Earth System Sciences, 2022)
Abstract. Meteorological forcing plays a critical role in accurately simulating the watershed hydrological cycle. With the advancement of high-performance computing and the development of integrated watershed models, simulating the watershed hydrological cycle at high temporal (hourly to daily) and spatial resolution (tens of meters) has become efficient and computationally affordable. These hyperresolution watershed models require high resolution of meteorological forcing as model input to ensure the fidelity and accuracy of simulated responses. In this study, we utilized the Advanced Terrestrial Simulator (ATS), an integrated watershed model, to simulate surface and subsurface flow and land surface processes using unstructured meshes at the Coal Creek Watershed near Crested Butte (Colorado). We compared simulated watershed hydrologic responses including streamflow and distributed variables such as evapotranspiration, snow water equivalent (SWE), and groundwater table driven by three publicly available, gridded meteorological forcings (GMFs) – Daily Surface Weather and Climatological Summaries (Daymet), the Parameter-elevation Regressions on Independent Slopes Model (PRISM), and the North American Land Data Assimilation System (NLDAS). By comparing various spatial resolutions (ranging from 400 m to 4 km) of PRISM, the simulated streamflow only becomes marginally worse when spatial resolution of meteorological forcing is coarsened to 4 km (or 30 % of the watershed area). However, the 4 km-resolution has much worse performance than finer resolution in spatially distributed variables such as SWE. Using the temporally disaggregated PRISM, we compared models forced by different temporal resolutions (hourly to daily), and sub-daily resolution preserves the dynamic watershed responses (e.g., diurnal fluctuation of streamflow) that are absent in results forced by daily resolution. Conversely, the simulated streamflow shows better performance using daily resolution compared to that using sub-daily resolution. Our findings suggest that the choice of GMF and its spatiotemporal resolution depends on the quantity of interest and its spatial and temporal scale, which may have important implications for model calibration and watershed management decisions.

Obituary: Kenneth Barclay Armitage (1925—2022) - E. L. Barthelmess; J. L. Koprowski; W. S. Fairbanks; R. M. Timm; C. M. Salsbury; D. H. Van Vuren; Daniel T. Blumstein (Journal of Mammology, 2022)

An analytical pipeline to support robust research on the ecology, evolution, and function of floral volatiles - K. E. Eisen; Robert A. Raguso; J. M. Powers; Diane R. Campbell (Frontiers in Ecology and Evolution, 2022)
Research on floral volatiles has grown substantially in the last 20 years, which has generated insights into their diversity and prevalence. These studies have paved the way for new research that explores the evolutionary origins and ecological consequences of different types of variation in floral scent, including community-level, functional, and environmentally induced variation. However, to address these types of questions, novel approaches are needed that can handle large sample sizes, provide quality control measures, and make volatile research more transparent and accessible, particularly for scientists without prior experience in this field. Drawing upon a literature review and our own experiences, we present a set of best practices for next-generation research in floral scent. We outline methods for data collection (experimental designs, methods for conducting field collections, analytical chemistry, compound identification) and data analysis (statistical analysis, database integration) that will facilitate the generation and interpretation of quality data. For the intermediate step of data processing, we created the R package bouquet , which provides a data analysis pipeline. The package contains functions that enable users to convert chromatographic peak integrations to a filtered data table that can be used in subsequent statistical analyses. This package includes default settings for filtering out non-floral compounds, including background contamination, based on our best-practice guidelines, but functions and workflows can be easily customized as necessary. Next-generation research into the ecology and evolution of floral scent has the potential to generate broadly relevant insights into how complex traits evolve, their genomic architecture, and their consequences for ecological interactions. In order to fulfill this potential, the methodology of floral scent studies needs to become more transparent and reproducible. By outlining best practices throughout the lifecycle of a project, from experimental design to statistical analysis, and providing an R package that standardizes the data processing pipeline, we provide a resource for new and seasoned researchers in this field and in adjacent fields, where high-throughput and multi-dimensional datasets are common.

Beaver dams overshadow climate extremes in controlling riparian hydrology and water quality - Nicholas J. Bouskill; Christian Dewey; Christian Dewey; Nicholas J. Bouskill; Patricia Fox; Dipankar Dwivedi; Scott Fendorf; Patricia Fox; Dipankar Dwivedi; Scott Fendorf; P. S. Nico; P. S. Nico (Nature Communications, 2022)
Hydrologic extremes dominate chemical exports from riparian zones and dictate water quality in major river systems. Yet, changes in land use and ecosystem services alongside growing climate variability are altering hydrologic extremes and their coupled impacts on riverine water quality. In the western U.S., warming temperatures and intensified aridification are increasingly paired with the expanding range of the American beaver-and their dams, which transform hydrologic and biogeochemical cycles in riparian systems. Here, we show that beaver dams overshadow climatic hydrologic extremes in their effects on water residence time and oxygen and nitrogen fluxes in the riparian subsurface. In a mountainous watershed in Colorado, U.S.A., we find that the increase in riparian hydraulic gradients imposed by a beaver dam is 10.7-13.3 times greater than seasonal hydrologic extremes. The massive hydraulic gradient increases hyporheic nitrate removal by 44.2% relative to seasonal extremes alone. A drier, hotter climate in the western U.S. will further expand the range of beavers and magnify their impacts on watershed hydrology and biogeochemistry, illustrating that ecosystem feedbacks to climate change will alter water quality in river systems.

The ecology and evolution of pathogens in a changing world (2022)
Infectious diseases are an integral part of natural ecosystems but also pose a serious threat to human health and agriculture. Understanding the multitude of factors shaping the epidemiology and evolution of pathogens is crucial for predicting and mitigating their effects, especially in a rapidly changing world. In this dissertation, I present four studies about how vaccination, emerging pathogens, and climate change affect the epidemiology and evolution of infectious disease. In the first chapter I consider the effects of toxin targeting vaccines, such as acellular pertussis vaccines, on the evolution of pathogen virulence. In the second chapter I map projections of the expected burden of the novel coronavirus SARS-CoV-2. In the third chapter I assess the risk for COVID-19 vaccines to drive the evolution of increased viral virulence. In the fourth chapter I investigate how climate change will alter the epidemiology of fungal plant pathogens using the flax rust system as a model. 3 Abstract.......................................................................................................................................... 3