Western Ecological Research Center (WERC)

Environmental Stressors

Filter Total Items: 34
Date published: October 30, 2017
Status: Active

Population Structure and Demography of the Least Bell’s Vireo and Southwestern Willow Flycatcher and Use of Restored Riparian Habitat

Riparian woodlands are highly productive ecosystems that support a disproportionately high fraction of regional biodiversity. They are also one of the most endangered terrestrial systems in temperate North America, and have been reduced to just 5% of their former extent in California and throughout the American southwest. These losses have been accompanied by steep declines in numerous plant...

Contacts: Barbara Kus
Date published: October 30, 2017
Status: Active

Native Plant Materials for Ecological Restoration of Degraded Drylands

There is a growing consensus among resource managers to use native plant materials for ecological restoration of degraded drylands. Some plant species may be suitable for re-introduction across broad environmental gradients. Other species may fail under narrower conditions, or their re-introduction may have genetic consequences for local ecotypes, particularly when adapting to future climate...

Contacts: Lesley DeFalco
Date published: October 30, 2017
Status: Active

Modeling Sea-Level Rise in San Francisco Bay Estuary

With sea level rise, how will the coastal habitats of the San Francisco Bay Estuary change over the next 100 years? Mapping and modeling studies by Dr. Karen Thorne, WERC scientists, and partners have produced scenarios for this important coastal ecosystem.

Date published: October 30, 2017
Status: Active

Mercury Bioaccumulation in Wetlands

Wetlands provide numerous ecosystem services, but also can be sources of methylmercury production and export. Click the next tab to learn how WERC's Dr. Josh Ackerman is evaluating the ecological factors that drive contaminant bioaccumulation in wetland-dependent fish and wildlife.

Contacts: Josh T Ackerman
Date published: October 30, 2017
Status: Active

Improving Understanding of Forest and Carbon Dynamics

The community's ability to understand and predict changes in forests and their feedbacks to the global carbon cycle increasingly relies on models spanning several scales of biological organization – from tree leaves to entire forested landscapes. Yet many model assumptions about key processes – such as tree growth and mortality – require long-term data that are sometimes difficult and time-...

Date published: October 30, 2017
Status: Active

Fire Severity Trends in the Western U.S.

How will increased drought affect forest fire severity? WERC’s Dr. Phil van Mantgem is testing the idea increased drought stress may affect forest fire severity independent of fire intensity. Drought stress prior to fire can affect tree health, potentially resulting in a higher sensitivity to fire-induced damage. Thus, with drought there may be ongoing increases in fire severity (the number of...

Date published: October 30, 2017
Status: Active

Ecology and Conservation of Golden Eagles in the Mojave Desert

Dr. Kathleen Longshore, in collaboration with Dr. Todd Esque, provides information to project the possible conflict between losses of habitat for foraging involved in the proposed development of alternative energy installations in the Mojave Desert and help develop advanced conservation efforts for the golden eagle. Information from this project will also inform California’s Desert Renewable...

Date published: October 30, 2017
Status: Active

Ecology and Conservation of Desert Bighorn Sheep

Dr. Kathleen Longshore’s goal is to understand how predator/prey relationships, disease and human-caused disturbance work separately and synergistically to impact bighorn sheep populations under variable ecological stress. Information from this project will provide managers with an understanding of specific and regional impacting factors that contribute to impact variation in population trends...

Date published: October 30, 2017
Status: Active

Ecology and Conservation of Amphibians in Northern California

This project improves our understanding of the ecology of amphibians in northern California and evaluates methods of managing landscapes and these imperiled species. In particular, Dr. Brian Halstead examines the distribution and demography of amphibians to understand factors that affect where amphibians are found and how populations change. He further explores the relationships of amphibians...

Contacts: Brian Halstead
Date published: October 30, 2017
Status: Active

Ecological Stressors - Rocky Coastlines, Mangroves, Marshes, Droughts, and Storms

Coastal estuaries that contain marshes and mangroves are currently being reshaped by changing ocean and atmospheric conditions through prolong drought, sea-level rise and increased extreme storm events. Many projected increases in sea-level are expected to result in loss of tidal wetlands and their component species. In addition, changing sediment loads, extreme tide and storm events, and...

Date published: October 30, 2017
Status: Active

Detection, Attribution, and Interpretation of Forest Changes

Dr. Nathan Stephenson and colleagues seek to determine what changes are occurring in forests, why they are occurring, and what they mean. For example, they have documented a long-term, apparently climatically-induced increase of tree mortality rates in otherwise undisturbed old forests across the western U.S., implying that these forests could become net sources of atmospheric carbon dioxide...

Date published: October 30, 2017
Status: Active

Desert Tortoise Ecology, Health, Habitat, and Conservation Biology

The desert tortoise is listed as “threatened” under the Endangered Species Act. USGS WERC scientists, along with project partners have been conducting long-term analyses on how changes in the southwestern deserts of the United States can affect desert tortoise populations. Dr. Todd Esque and his team are investigating how habitat disturbances and restoration projects influence tortoise...

Contacts: Todd Esque