Southwest

California - one of the nation's most populous states - hosts extensive public lands, crown-jewel national parks, and diverse natural resources. Resource managers in federal, state, tribal, and local agencies face challenges due to environmental changes and extreme events such as severe droughts, heat waves, flood events, massive wildfires, and forest dieback. However, state-of-the-art...

Sagebrush steppe is one of the most widely distributed ecosystems in North America. Found in eleven western states, this important yet fragile ecosystem is dominated by sagebrush, but also contains a diversity of native shrubs, grasses, and flowering plants. It provides critical habitat for wildlife like pronghorn and threatened species such as the greater sage-grouse, and is grazed by...

The Southwest U.S. is experiencing hotter droughts, which are contributing to more frequent, severe wildfires. These droughts also stress vegetation, which can make it more difficult for forests to recover after fire. Forest regeneration in burned areas may be limited because seeds have to travel long distances to recolonize, and when they do arrive, conditions are often unfavorably hot...

Changing climate conditions could have significant impacts on wildlife health. Shifts in temperature and precipitation may directly affect the occurrence of disease in fish and wildlife by altering their interactions with pathogens (such as the bacterium that causes Lyme disease), helping vectors like mosquitoes and ticks expand their range, or speeding up the time it takes for a...

Fire size, frequency, overall area burned, and severity are increasing across many vegetation types in the southwestern U.S. In many cases, large contiguous areas are burning repeatedly at high severity, triggering vegetation type conversions (VTC), where once-dominant coniferous forests fail to return to their pre-fire state, often transitioning to shrub- or grass-dominated systems...

The Colorado River is a crucial water source for millions of people in the Southwest. Warming temperatures, clearly documented in climate records for the Colorado River basin, are having an impact on the amount of annual streamflow yielded from rain and snow. Recent work has revealed that warming temperatures have played an increasingly important role over the past decades, both...

The Mediterranean ecosystems of southern California are some of the most ecologically diverse systems in the world. The diversity of plants and animals, as well as high rates of endemism, make the area a biodiversity hotspot. High diversity in plant and animal species contributes greatly to the health and productivity of ecosystems, and plays an important role in the local and state...

A major goal of the Climate Science Center network is to conduct science and develop timely science products and tools that are directly relevant and useful to decision-makers and natural resource managers. A crucial first step in producing this actionable science is understanding the highest priority science and information needs of natural resource managers and planners. Through this...

Estuaries are located at the interface where rivers meet the sea, creating unique ecosystems with complex physical and biological processes. Coastal wetlands provide essential ecosystem services to people, including flood protection from high tides and storm surges, commercial fisheries, carbon sequestration, improved water quality, and wildlife food and habitat. Coastal wetlands are...

The impacts of climate change are already being observed and felt in our ecosystems and communities. Land and resource managers, planners, and decision-makers are looking for the best scientific information to guide their decisions about adapting to and mitigating the effects of climate change now and in the future. To address this need, a primary goal of the Southwest Climate Science...

The desert grasslands of the southwestern United States support many wildlife species of management concern and economic value. The American pronghorn, for example, is a game species that contributes to local and state economies. Climate extremes, including severe droughts, heat waves, and atmospheric river events, are expected to occur more frequently in the Southwest. These extremes...

In the dry southwestern United States, snowmelt plays a crucial role as a water source for people, vegetation, and wildlife. However, snow droughts significantly lower snow accumulations, disrupting these critical water supplies for local communities and ecosystems. Despite its large influence on land- and water-resource management, snow drought has only recently been properly defined...