Drought, Fire, and Forests

New assessment provides critical information for managing U.S. forests in the future

The new assessment, Drought Impacts on U.S. Forests and Rangelands, provides critical information for the recently re-authorized National Integrated Drought Information System and meets the National Climate Assessment need for scientific information on drought.

The 2015 wildfire season was the costliest on record, with about $1.71 billion spent by the Forest Service on fighting fires. During one particular week in the summer of 2015, fire-fighting cost $1.6 million per hour. Most of the fires of 2015 hit western states like drought stricken California, where fire risk remains high due to 4 years of drought that’s resulted in the deaths of millions of trees.

As temperatures rise and precipitation patterns change under climate change, it’s likely that drought – and associated disturbances such as insect outbreaks and wildfires – will only get worse across many areas of the U.S. Large stand-level changes in forests are already underway in many parts of the West, but all U.S. forests can be impacted by drought.

In the South, the 2011 drought set off timber fires in both Georgia and Texas. In 2007, over a third of the region was classified in “exceptional” drought and the city of Atlanta declared a water emergency. That same year, Georgia experienced its largest wildfire on record when the Georgia Bay Complex burned 441,705 acres of forest.

How can forest managers address the impacts of short-term and long-term drought conditions and manage their lands for a hotter and drier future? A newly published report by the U.S. Forest Service provides a national assessment of the impacts of drought on the nation’s forests and rangelands and gives the scientific foundation required to develop strategies that managers can use to increase the resiliency of their forests.

“Management actions can either mitigate or exacerbate the effects of drought,” said Jim Vose, the Forest Service Southern Research Station (SRS) scientist who served as one of lead editors of the report. “This synthesis establishes the scientific foundation needed to manage forests for drought resiliency and adaptation.”

Forested land alone comprises nearly one-third of the total land area of the U.S.—the single largest classification of land cover in the country. Although the assessment is national in scope, it identifies and discusses key regional concerns such as large-scale insect outbreaks and increased wildfire risk in the western U.S.

“This is not to say that drought doesn’t affect forest resources of the East,” says Vose, project leader of the SRS Center for Integrated Forest Science. “The key difference between the western and eastern U.S. is the scale, frequency, and pace of change. The less obvious impacts in the East could have equal or greater consequences because of the large human populations living near forests and relying on them for many key purposes, including clean water.” For example, forested watersheds are critical for the water supplies of many cities, including New York City and Atlanta.

Major findings from the report include:

  • Drought projections suggest that some regions will become drier and that most will have extreme variations in precipitation.
  • Even if current drought patterns remained unchanged, warmer temperatures will amplify drought effects.
  • Drought and warmer temperatures will increase risks of large-scale insect outbreaks and larger wildfires, especially in the western U.S.
  • Drought and warmer temperatures will accelerate tree and shrub death, changing habitats and ecosystems in favor of drought-tolerant species.
  • Forest-based products and values – such as timber, water, habitat, and recreation opportunities – will be negatively impacted.
  • Forest and rangeland managers can mitigate some of these impacts and build resiliency in forests through appropriate management actions.

Learn more about drought impacts on southern forests and possible strategies to increase resilience.

Edited by Forest Service scientists in partnership with Duke University and published by the Southern Research Station, Drought Impacts on U.S. Forests and Rangelands provides critical information for the recently re-authorized National Integrated Drought Information System and meets the National Climate Assessment need for scientific information on drought.

More than 70 scientific experts from the Forest Service, other federal agencies, research institutions, and universities across the U.S. participated in the synthesis. The key issues addressed in the synthesis were identified from a series of virtual workshops with scientists and stakeholders.

Access the full report.

For more information, email Jim Vose at jvose@fs.fed.us 

Access the latest publications by SRS scientists.