Natural Stressors

Science Center Objects

The status and trends of organisms, habitats and ecosystems is often controlled by environmental and anthropogenic stressors that have the potential to impact the health and productivity of lands and waters of management concern.

USGS studies related to natural stressors that are part of the Status and Trends program are listed below.


WERC Fire Scar
Trees with fire scars. (Credit: Nathan Stephenson. Public domain.)

Modeling Disturbance and Ecosystem Change at Landscape Scales

Science Center: Forest and Rangeland Ecosystem Science Center

We are using a spatially-explicit, stochastic, landscape simulation model (LANDIS-II) to project potential future changes in forest composition and fire regimes under different land use and climate change scenarios in southern boreal forests, Rocky Mountain forests, and Great Basin aspen woodlands. 

► Learn more about landscape-scale modeling


Stressors to Greater Sage-Grouse

WERC Scientist conducting elevation surveys in a salt marsh
WERC scientist conducting elevation surveys in salt marsh (Credit: Karen Thorne, USGS WERC. Public domain.)

Science Center: Western Ecological Research Center

The Greater Sage-grouse is a small bird found only in the sagebrush steppe of the Great Basin. Invasions of non-native grasses, evolving wildfire patterns, grazing from livestock, and human land uses are changing this unique ecosystem. 

► Learn more about stressors to greater sage-grouse


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

Science Center: Western Ecological Research Center

Massive winter storm over the US from MODIS
Massive winter storm mosaic from three images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite.(Credit: NASA Goddard MODIS Rapid Response Team. Public domain.)

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. 

► Learn more about stressors along the coasts


Drought and Western Forests

Science Center: Western Ecological Research Center

USGS WERC's Dr. Phil van Mantgem and his collaborators are using plot-based methods to describe change and vulnerability to drought in the forests of the western United States. 

► Learn more aboout drought and forests


Image: Giant Sequoias and Hotter Droughts
Giant sequoias have fared better than other tree species in California's recent hotter drought, but many have shown unprecedented foliage dieback in response to the drought.(Credit: Nathan Stephenson, USGS. Public domain.)

Fire Severity Trends

Science Center: Western Ecological Research Center 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 trees killed), even when there is no change in fire intensity (the amount of heat released during a fire).

► Learn more about fire severity trends


Ecological Stressors

Science Center: Wetland and Aquatic Research Center

Research into the cause and mitigation of environmental and anthropogenic stressors that potentially impact the health and productivity of lands and waters of management concern. Current focal areas include wildland fire, extreme storm events (droughts, floods, and hurricanes), climate change (sea level, warming, and precipitation), mining, and timbering.

► Learn more about ecological stressors 



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