Control of litter decomposition in a subalpine meadow-sagebrush steppe ecotone under climate change
The role of larval cases in reducing aggression and cannibalism among caddisflies in temporary wetlands
Environmental sensitivity of sexual and apomictic Antennaria: do apomicts have general-purpose genotypes?
Structure and composition of natural ferrihydrite nano-colloids in anoxic groundwater
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 composi
Removing flowers of a generalist plant changes pollinator visitation, composition, and interaction network structure
Abstract Pollination is essential for ecosystem functioning, yet our understanding of the empirical consequences of species loss for plant–pollinator interactions remains limited. It is hypothesized that the loss of abundant and generalized (well‐connected) species from a pollination network will ha
Evolutionary dynamics of an <i>Ipomopsis</i> hybrid zone: confronting models with lifetime fitness data
Interspecific hybridization is a recurring aspect of the evolution of many plant and animal groups. The temporal dynamics of hybrid zones and the evolutionary consequences of hybridization should depend on fitness of parental and hybrid individuals expressed in different environments. We measured li
Three Harpellales that live in one species of aquatic chironomid larva
Two new species of harpellid gut fungi, Smittium fecundum and Stachylina robusta, were found living in larvae of Psectrocladius sp. (Diptera: Chironomidae) in a high-altitude kettle pond in the Rocky Mountains of Colorado. A third species of Harpellales, Smittium mucronatum, previously known only fr
Heterospecific prey and trophic polyphenism in larval tiger salamanders
Polyphenisms (environmentally cued polymorphisms) are ubiquitous, yet the specific proximate mechanisms producing alternative morphs are generally not well known. We tested hypotheses for the role of large heterospecific prey in the cannibalistic polyphenism within larval tiger salamanders, Ambystom
The Pending Extinction of the Uncompahgre Fritillary Butterfly
Previous mark‐recapture studies and population size estimates indicated that in the 1980s populations of the endangered Uncompahgre fritillary ( Boloria acrocnema ) declined precipitously, apparently leading to extirpation at its type locality. This locality and a nearby second site, both high in th
Density-dependent demographic responses of a semelparous plant to natural variation in seed rain
The link between reproductive and vegetative ecology of flowering plants is rarely explored, despite its importance for understanding population processes and fitness. This link can be studied by using experimental or natural variation in seed input to the soil to assess how reproductive success aff
Spatial variations in the fate and transport of metals in a mining-influenced stream, North Fork Clear Creek, Colorado
Visual-MINTEQ was used to compare observed and model-calculated percentage particulate Cu and Zn as influenced by sorption to both HFO and HMO and aqueous complexation with dissolved organic carbon, and differences between observed and modeled particulate varied significantly between sites and seaso
Fur color diversity in marmots
Fur color that differs from the typical shades of brown and gray occurs in eight species of marmots. Albinism generally is rare whereas melanism is more common. Melanism may persist in some populations at low frequencies averaging 16.1% in M. monax and in M. flaviventris for as long as 80 years. Whi
New material of<i>Dinochelys whitei</i>Gaffney, 1979, from the Dry Mesa Quarry (Morrison Formation, Jurassic) of Colorado
ABSTRACT A specimen of a juvenile individual of Dinochelys from the Dry Mesa Quarry, Morrison Formation, provides the first record of the skull and neck in this genus. Dinochelys is interpreted as related to Glyptops on the basis of a similar development of sculpture on the vertebral scutes of juven
Trout predators and demographic sources and sinks in a mayfly metapopulation
Habitat patches often differ in environmental conditions, and the degree of environmental heterogeneity among patches is thought to influence population dynamics at the regional (metapopulation) scale. In a previous study, I found evidence of a source– sink dynamic in a metapopulation of the mayfly
Ontogenetic and sex differences influence alarm call responses in mammals: A meta-analysis
Animals respond to alarm calls by increasing their antipredator behavior; however, responses may consistently differ by age or sex. Although several adaptive explanations have been proposed to account for age-dependent antipredator behavior, similar explanations are rarely extended to sex-specific r
Nitrogen and carbon flow from rock to water: Regulation through soil biogeochemical processes, Mokelumne River watershed, California, and Grand Valley, Colorado
Soil denitrification is an ecologically important nitrogen removal mechanism that releases to the atmosphere the greenhouse gas N2O, an intermediate product from the reduction of NO3− to N2. In this study we evaluate the relationship between soil carbon and denitrification potential in watersheds wi
Modeling geogenic and atmospheric nitrogen through the East River Watershed, Colorado Rocky Mountains
There is a growing understanding of the role that bedrock weathering can play as a source of nitrogen (N) to soils, groundwater and river systems. The significance is particularly apparent in mountainous environments where weathering fluxes can be large. However, our understanding of the relative co
Polyploidy in Indian paintbrush (<i>Castilleja</i>; Orobanchaccae) species shapes but does not prevent gene flow across species boundaries
• Premise of study: A difference in chromosome numbers (ploidy variation) between species is usually considered a major barrier to gene flow. Therefore, it is surprising that little is known about whether ploidy variation, both within and among species, influences spatial patterns of interspecific h
Functions of staminate flowers in andromonoecious <i>Pseudocymopterus montanus</i> (Apiaceae, Apioideae)
Abstract The pollen donor and pollinator attractor hypotheses are non‐exclusive alternative explanations for the functions of the staminate flowers of andromonoecious plants. We tested assumptions and predictions of both hypotheses using the andromonoecious perennial Pseudocymopterus montanus (Apiac
Parasite infection and host dynamics in a naturally fluctuating rodent population
Parasites can both influence and be affected by host population dynamics, and a growing number of case studies support a role for parasites in causing or amplifying host population cycles. In this study, we examined individual and population predictors of gastrointestinal parasitism on wild cyclic m
