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Publications

Filter Total Items: 1987

Lethal impacts of selenium counterbalance the potential reduction in mercury bioaccumulation for freshwater organisms☆

Mercury (Hg), a potent neurotoxic element, can biomagnify through food webs once converted into methylmercury (MeHg). Some studies have found that selenium (Se) exposure may reduce MeHg bioaccumulation and toxicity, though this pattern is not universal. Se itself can also be toxic at elevated levels. We experimentally manipulated the relative concentrations of dietary MeHg and Se (as selenomethion
Authors
Jacqueline R. Gerson, Rebecca A. Consbrock, Collin Eagles-Smith, Emily S. Bernhardt, David Walters

Flight altitudes of raptors in southern Africa highlight vulnerability of threatened species to wind turbines

Energy infrastructure, particularly for wind power, is rapidly expanding in Africa, creating the potential for conflict with at-risk wildlife populations. Raptor populations are especially susceptible to negative impacts of fatalities from wind energy because individuals tend to be long-lived and reproduce slowly. A major determinant of risk of collision between flying birds and wind turbines is t
Authors
Christopher J W McClure, Leah Dunn, Jennifer D McCabe, Brian W. Rolek, Andre Botha, Munir Virani, Ralph Buij, Todd E. Katzner

A riverscape approach reveals downstream propagation of stream thermal responses to riparian thinning at multiple scales

Hydrological connectivity in river networks influences their response to environmental changes as local effects may extend downstream via flowing water. For example, localized changes in riparian forest conditions can affect stream temperatures, and these effects may propagate downstream. However, studies evaluating stream temperature responses to riparian forest management have not considered cum
Authors
David A. Roon, Jason B. Dunham, Christian E. Torgersen

Evaluating the role of active management in mature Douglas-fir (Pseudotsuga menziesii) stands for songbird conservation

Forest birds, particularly those associated with late-successional forests, are of widespread conservation interest. Although birds are among the more widely studied taxa of forest wildlife, relatively few studies have examined the long-term effects of active management (i.e., intentional stand density reduction) on the forest bird assemblage. This is an important omission, as changes in stand str
Authors
Neil Williams, Joan Hagar, Matthew Powers

Integrating regional and local monitoring data and assessment tools to evaluate habitat conditions and inform river restoration

RRestoring degraded rivers requires initial assessment of the fluvial landscape to identify stressors and riverine features that can be enhanced. We associated local-scale river habitat data collected using standardized national monitoring tools with modeled regional water temperature and flow data on mid-sized northwest U.S. rivers (30–60 m wide). We grouped these rivers according to quartiles of
Authors
Francine H. Mejia, Jason M Connor, Phil R Kaufmann, Christian E. Torgersen, Eric K Berntsen, Todd Andersen

Fish response to successive clearcuts in a second-growth forest from the central Coast range of Oregon

Research dating back to the 1950 s has documented negative effects from harvesting of primeval forests on stream ecosystems of the Pacific Northwest. By the early 1990 s, state and federal forest practice rules governing timber harvest were modified throughout North America to better protect aquatic habitats and biotic resources, principally salmonids. These rules inspired a generation of studies
Authors
D. S. Bateman, Nathan Chelgren, Robert E. Gresswell, Jason B. Dunham, David Hockman-Wert, D. W. Leer, K. D. Bladon

Early growth and ecophysiological responses of Koa (Acacia koa A. Gray) seedlings to reduced water and phosphorus

Sites in need of restoration typically have one or more environmental factors that limit seedling establishment. Identifying ecophysiological responses to environmental stressors can provide important insights into mitigating measures that would allow seedlings to overcome such constraints to survival. Koa (Acacia koa A. Gray) is a nitrogen-fixing tree species endemic to Hawaiʻi that is highly val
Authors
Kaitlin Gerber, Amy Ross-Davis, Steven Perakis, Anthony S. Davis

Intraspecific variation mediates density dependence in a genetically diverse plant species

Interactions between neighboring plants are critical for biodiversity maintenance in plant populations and communities. Intraspecific trait variation and genome duplication are common in plant species and can drive eco-evolutionary dynamics through genotype-mediated plant–plant interactions. However, few studies have examined how species-wide intraspecific variation may alter interactions between
Authors
Andrii Zaiats, Matthew Germino, Marcelo D. Serpe, Bryce Richardson, Trevor Caughlin

Small mammal shooting as a conduit for lead exposure in avian scavengers

Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their Pb exposure
Authors
Garth Herring, Collin Eagles-Smith, John Goodell, Jeremy A. Buck, James Willacker

Seasonal and age-related variation in daily travel distances of California Condors

Despite a dramatic recovery from the brink of extinction, California Condors (Gymnogyps californianus) still face significant anthropogenic threats. Although condor movement patterns across large temporal scales are understood, less is known about their movements on a fine temporal scale. We used a trajectory-based analysis of GPS telemetry data gathered from condors during 2013 to 2018 to investi
Authors
Jonathan C. Hall, Insu Hong, Sharon Poessel, Melissa A. Braham, Joseph Brandt, Joseph Burnett, Todd E. Katzner

An updated assessment of status and trend in the distribution of the Cascades frog (Rana cascadae) in Oregon, USA

Conservation efforts need reliable information concerning the status of a species and their trends to help identify which species are in most need of assistance. We completed a comparative evaluation of the occurrence of breeding for Cascades Frog (Rana cascadae), an amphibian that is being considered for federal protection under the U.S. Endangered Species Act. Specifically, in 2018–2019 we resur
Authors
Adam Duarte, Christopher Pearl, Brome McCreary, Jennifer Rowe, Michael J. Adams

The role of genome duplication in big sagebrush growth and fecundity

PremiseAdaptive traits can be dramatically altered by genome duplication. The study of interactions among traits, ploidy, and the environment are necessary to develop an understanding of how polyploidy affects niche differentiation and to develop restoration strategies for resilient native ecosystems.MethodsGrowth and fecundity were measured in common gardens for 39 populations of big sagebrush (A
Authors
Bryce Richardson, Matthew Germino, Marcus V Warwell, Sven Buerki