Ecological Drought in the Northwest United States: Challenges and opportunities for management of diverse landscapes
The northwestern United States is home to a diverse landscape, from the wet, coastal shores of Oregon and Washington, over the complex mountain ranges, to the dry desert landscapes of western Idaho. The nature of the region’s landscape and topography contributes to a unique climate and challenges resource managers to find solutions that work across a range of different environments.
Now, changes in climate are presenting the region’s managers with new challenges. Impacts of climate change in the region include changes in precipitation, the duration of snowpack, the timing of spring thaw, and the amount of soil moisture. These changes have subsequently contributed to increases in wildfires, insect outbreaks, drought, and floods. For example, drought conditions along the Olympic Peninsula have resulted in forest fires occurring in areas where they have never been recorded before. Managers are faced with the challenge of adapting to these changes and require new methods of drought management that consider both changing climate conditions and the landscape diversity of the Northwest.
In light of these concerns, the Department of the Interior Northwest Climate Science Center (NW CSC) is working to identify how drought will manifest itself throughout the region and what these changing conditions could mean for ecosystems and wildlife. In February 2017, a group of climate and ecological experts met to discuss ecological drought in the Northwest, and identified several core issues:
Climate change is changing drought in the Northwest: Changes in drought are leading to more frequent, bigger, and hotter fires that lead to increased soil erosion, pest introduction, and flooding due to greater runoff.
Managing for wetter, warmer winters and drier, hotter summers: Weakening winds has reduced the amount of moist maritime air reaching the mountain ranges, resulting in wetter winters and drier summers.
Change in streamflow impact aquatic ecosystems: Many areas within the region have seen a 20 to 80 percent decrease in April snowpack, resulting in changes to streamflow. Aquatic species can be extremely sensitive to ecological drought because they depend on seasonal snowmelt for fresh, cool water. Trout and salmon depend on predictable streamflow to migrate to the ocean. Therefore, changes in streamflow could have severe ecological, cultural, and economic implications for the Northwest.
Drought amplifies stressors across the Northwest landscapes: Earlier spring snowmelt and increasing air temperatures are closely linked with increased frequency of large wildfires. Increased wildfires, insect outbreaks, water deficits, and higher temperatures increase tree stress and mortality.
These changes in temperature and precipitation patterns in the Northwest have the potential to result in major ecological, social, and economic impacts. In response, the NW CSC is working collaboratively with managers and scientists to evaluate drought adaptation actions. As drought becomes more common and severe in the region, the NW CSC is poised to help scientists, managers, tribal leaders, and policy makers take creative and effective actions for preserving the Northwest’s natural and cultural heritage.
The February workshop was hosted in partnership by the NW CSC, the University of Maryland Center for Environmental Science Integration & Application Network, and the USGS National Climate Change and Wildlife Science Center. This was the seventh in a series of eight workshops being held across the United States, each in a different region. Each workshop results in a four-page informational document that synthesizes the current understanding of ecological drought in the region.
To view the informational document from the Northwest workshop and learn more about ecological drought in the Northwest, please click here.
Learn more about Ecological Drought in other regions of the U.S. here
Graphic: Trends in April snowpack in the Western United States, 1955–2016. Snow pack is measured in terms of snow water equivalent. Blue circles represent increased snowpack; red circles represent a decrease (Adapted from Mote and Sharp,) Diagram: Current and future status of drought in the Northwest Credit: UMCES-IAN