A patch of bright green corn lilies glow in the sunlight amid an otherwise barren forest floor and blackened trees stretching toward a blue sky. The lilies indicate the presence of shallow groundwater in a post-fire monitoring plot in the Mendocino National Forest after a large wildfire. Photo by Ryan P. Mikulovsky, USFS.
BY MORRIS C. JOHNSON, KAREN DANTE-WOOD
Large, severe wildfires have become the norm in much of the country, including in seasonally dry forests across the interior of the western United States. Most of the tree stands are adapted only to low-intensity fires. Extreme wildfires can kill them and result in long-term changes to the ecosystem.
For example, in the last few years, nearly 88 percent of the Mendocino National Forest in the Coastal Mountain Range of northwestern California has burned. The damage was caused by the Mendocino Complex in 2018 and the August Complex in 2020. Together, these wildfires burned over 1.4 million acres.
After a fire passes, woody debris from dead and damaged trees can build up. It can exacerbate the severity of future wildfires and impede natural forest recovery. Restoration efforts can help native vegetation and tree stands return to the affected area while reducing woody debris accumulation that could fuel the next wildfire.
Current mapping tools and models for forest data, however, lack the resolution necessary to design site-specific restoration treatments following large-scale wildfires.
Morris C. Johnson with the U.S. Department of Agriculture (USDA) Forest Service developed a study to help fire and forest managers restore healthy tree stands after a large wildfire. Johnson submitted the proposal to the Joint Fire Science Program, which invests in important research to help land managers with decision making. The Bipartisan Infrastructure Law provided additional funding for the program, some of which is being invested in Johnson’s proposal.
Johnson and his team at the Forest Service’s Pacific Wildland Fire Sciences Laboratory in Seattle will establish a network of long-term monitoring plots within the footprint of the Mendocino Complex and August Complex. They will use the plots to monitor post-fire tree stands, including their structural condition, accumulation of dead wood, seedling survival, and shrub regeneration.
Through field measurements and statistical modeling, they will assess current conditions. They will also use a simulator that creates computer models to predict long-term snag and woody fuel dynamics. In close collaboration with forest managers at the Shasta Trinity and Mendocino national forests, they will develop maps of current conditions and departures from desired conditions.
This project will help forest and fire managers plan post-fire interventions to steer the landscape toward desirable conditions. It will identify areas that need management intervention and inform reforestation strategies to improve the resilience of the forest to wildfires. By fostering a healthy ecosystem, this project will help establish forest conditions that can withstand or recover from disturbances caused by climate change, wildfires, pests, and other pressures.
Morris C. Johnson is a research fire ecologist with the USDA Forest Service. He works in the Pacific Wildland Fire Sciences Laboratory at the Pacific Northwest Research Station in Seattle.
Karen Dante-Wood is the technology transfer specialist for the Joint Fire Science Program at the National Interagency Fire Center in Boise, Idaho.