Drought has lowered water levels in the reservoir at Boca Dam, on the Truckee River in Nevada. Photo by Bureau of Reclamation.
Drought—a normal part of the climate cycle—has come and gone for millennia, at times causing ecological or economic devastation. The Pacific Northwest Research Station develops research that can help land and watershed managers avoid this devastation wherever possible. A recent report assesses current trends, describes projections of drought across the United States in the 21st century, and offers region-specific management options.
Climate change will increase the odds of worsening drought. Based on climate projections, the report concludes that all regions of the United States are predicted to experience marked increases in drought conditions after 2040. Even if current drought regimes remain unchanged, the higher temperatures associated with climate change will exacerbate water stress.
However, in places where drought has been prevalent, many forest and rangeland species have evolved a variety of survival mechanisms. Understanding these mechanisms enables land managers to take concrete steps toward adaptation on national forests and other federal lands.
Co-editor David L. Peterson made every effort to focus on management solutions in the report. “Yes, some negative things will almost certainly happen, but we can soften the impact through good planning and timely actions,” he said. For forests, a common tactic is to reduce water demand by managing stands at a lower density and favoring species that either require less water or can tolerate drought.
The report includes region-specific chapters describing management options for increasing resilience to drought for Alaska and Pacific Northwest, California, Hawai‘i and U.S.-affiliated Pacific Islands, the Interior West, Great Plains, Northeast and Midwest, and Southeast. These build on a comprehensive state-of-science synthesis published in 2016 titled Effects of Drought on Forests and Rangelands in the United States: A Comprehensive Science Synthesis.
“In Alaska and the Northwest, water resources are the most important issue in the near term, mostly as a result of decreasing snowpack, receding glaciers, and hotter summers,” said Peterson. “Droughts along the Pacific coast during the past decade are probably just a taste of what will occur after around 2050.”
Fortunately, there is time to prepare for those more chronic droughts. If drought-informed practices are institutionalized as part of agency operations, then planning and management will be more effective, and “crisis management” can be avoided.