Publications

Morphological intermediates between Tamarix ramosissima or T. chinensis (saltcedars) and T. aphylla (athel) were found recently in three locations in the southwestern USA, and were assumed to be hybrids or a previously unreported species. We sequenced chloroplast and nuclear DNA from putative parental and hybrid morphotypes and hybrid status of morphological intermediates was supported

No abstract available.

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that cascade among...

Primers for five polymorphic microsatellite loci were developed for the midget faded rattlesnake (Crotalus viridis concolor), a rare subspecies of western rattlesnake (Crotalus viridus) found only in parts of Wyoming, Colorado, and Utah. Five polymorphic microsatellites were isolated, four of which had relatively high levels of diversity (eight to nine alleles). We found only two...

The Amphibian Research and Monitoring Initiative (ARMI) began in 2000 as an attempt by the United States Geological Survey to determine the status and trends of amphibians on federal lands in the United States and its territories. ARMI research focuses on determining causes of declines, if observed, developing new techniques to sample populations and analyze data, and disseminating...

The primary objectives of this evaluation were to improve the performance of the Whooping Crane Habitat Suitability model (C4R) used by the U.S. Fish and Wildlife Service (Service) for defining the relationship between river discharge and habitat availability, and to assist the Service in implementing improved model(s) with existing hydraulic files. The C4R habitat model is applied at...

Blossom is an R package with functions for making statistical comparisons with distance-function based permutation tests developed by P.W. Mielke, Jr. and colleagues at Colorado State University (Mielke and Berry, 2001) and for testing parameters estimated in linear models with permutation procedures developed by B. S. Cade and colleagues at the Fort Collins Science Center, U.S...

Future drought is projected to occur under warmer temperature conditions as climate change progresses, referred to here as global-change-type drought, yet quantitative assessments of the triggers and potential extent of drought-induced vegetation die-off remain pivotal uncertainties in assessing climate-change impacts. Of particular concern is regional-scale mortality of overstory trees...

Knowledge of factors influencing animal distribution and abundance is essential in many areas of ecological research, management, and policy-making. Because common methods for modeling and estimating abundance (e.g., capture–recapture, distance sampling) are sometimes not practical for large areas or elusive species, indices are sometimes used as surrogate measures of abundance. We...

No abstra

The newly described Gunnison sage-grouse (Centrocercus minimus) is a species of concern for management because of marked declines in distribution and abundance due to the loss and fragmentation of sagebrush habitat. This has caused remaining populations to be unusually small and isolated. We utilized mitochondrial DNA sequence data and data from 8 nuclear microsatellites to assess the...

Communications during fire events are complex. Nevertheless, training fire information officers to plan fire communications before events, and to communicate during fires in a way that accurately and promptly informs residents in fire-affected areas, can increase effectiveness, reduce anxiety, ensure residents have accurate information on which to act, help them make better decisions...