PremiseIndustrialization and human activities have elevated temperatures and caused novel precipitation patterns, altering soil moisture and nutrient availability. Predicting evolutionary responses to climate change requires information on the agents of selection that drive local adaptation and infl

• 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

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

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

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

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

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

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

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

AbstractMost herbivorous insect species are restricted to a narrow taxonomic range of host plant species. Herbivore species that feed on mustard plants and their relatives in the Brassicales have evolved highly efficient detoxification mechanisms that actually prevent toxic mustard oils from forming

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

The increase in corolla length provides a rare example of a match between predicted and observed evolution of a plant trait in natural populations. The clinal properties are consistent with the hypothesis that habitat-mediated divergent selection on vegetative traits and pollinator-mediated selectio

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

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 ecology of quaking aspen was studied in Gunnison County, Colorado. In the study area, aspen stands often take the form of small islands surrounded by fescue grasslands. At its upper altitudinal limits, aspen generally abuts the spruce-fir forest. The greatest number of trees were 4- to 7-in DBH

Kerans, B. L., Peckarsky, B. L. and Anderson, C. 1995. Estimates of mayfly mortality: is stonefly predation a significant source? - Oikos 74: 315-323. Field experiments and surveys were canied out in a Rocky Mountain alpine stream during the summers of 1990 and 1992 to estimate the proportion of nat

Although reciprocity of affiliative exchanges within cohorts increased as individuals matured, competition among genetic relatives emerged early in ontogeny and persisted into adulthood, suggesting that close affiliates are each other's closest competitors.

Context The ability to identify priority habitat is critical for species of conservation concern. The designation of critical habitat under the US Endangered Species Act 1973 identifies areas occupied by the species that are important for conservation and may need special management or protection. H

Mountain big sagebrush (Artemisia tridentata Nutt. ssp. vaseyana) covers large areas in arid regions of western North America. Climate-change models predict a decrease in the range of sagebrush, but few studies have examined details of predicted changes on sagebrush growth and the potential impacts