Study reveals nearly 1.5 times higher risk of high-severity wildfires on industrial private lands

Forests managed by timber companies are significantly more prone to destructive wildfires than publicly owned forests, according to new research led by the University of Utah, University of California, Berkeley, and the United States Forest Service.

Industrial forests face higher wildfire risk

The study found that the odds of high-severity wildfire were nearly one-and-a-half times higher on industrial private land than on public land. Industrially managed forests tend to create the conditions that megafires thrive on—densely packed, evenly spaced trees with continuous vegetation that connects the understory to the canopy.

Published on August 20, 2025, in Global Change Biology, the study is the first to identify how extreme weather conditions and forest management practices jointly influence wildfire severity.

“That’s a really hopeful finding because it means that we can adjust how we manage these landscapes to impact the way fires move through them,” said Jacob Levine, postdoctoral researcher at the University of Utah and lead author of the study. “Strategies that reduce density by thinning out both small and mature trees will make forests more robust and resilient to fire in the future.”

Lidar reveals forest structures before the fires

The research team leveraged a rare airborne lidar dataset to create three-dimensional maps of forest structure before wildfires swept through the region.

In 2018, the U.S. Forest Service, U.S. Geological Survey, and NASA executed lidar scans over Plumas National Forest and neighbouring private properties in California’s northern Sierra Nevada. Within a year, from 2019 to 2021, five significant wildfires, including the Dixie Fire, the largest in California’s documented history, ravaged 70% of the study region, incinerating 1.1 million acres.

“We have a really detailed picture of what the forest looked like immediately before these massive fires. It’s an unbelievably valuable thing to have,” Levine said. “Understanding the forest structures that lead to high-severity fire allows us to target mitigation strategies to get ahead of this massive fire problem while still producing enough timber to meet market demand.”

How management practices drive fire severity

Industrial forestry practices often rely on plantation-style management, where trees are planted in dense, uniform grids after clear-cutting. This approach leaves forests highly susceptible to crown fires.

“You can think about stacking a bunch of matches together in a grid—that’s going to burn a lot better than if you have those matches dispersed as smaller clumps,” Levine explained. “A bigger fire can easily reach the canopy in dense forests. Then it’s ripping through one tree after another, tossing out chunks of burning material miles in advance. It’s a different story.”

Public lands, meanwhile, are managed for multiple purposes including recreation, grazing, wildlife habitat, restoration, and timber production. However, public agencies face legal and political hurdles to thinning projects, as environmental groups often challenge proposals to remove trees.

Both public and private management strategies, the researchers note, require significant improvements to reduce megafire risk. Most Sierra Nevada tree species are poorly adapted to recover from high-severity fires, and large tracts of forest risk converting into shrublands or grasslands.

“This has major implications for timber, but also for carbon sequestration, water quality, wildlife habitat and recreation,” Levine said. “Shrub and grasslands can be beautiful, but when we think of the Sierra Nevada we picture majestic forests. Without major changes in forest management, future generations could inherit a landscape that looks very different than the one we cherish today.”

Key Takeaways

• Wildfire severity is nearly 1.5 times higher on industrial private lands compared to public forests.
• Lidar data provided unprecedented 3D maps of forests before megafires struck California’s northern Sierra Nevada.
• Dense, plantation-style forestry practices on private lands create conditions favorable to megafires.
• Both public and private lands need improved management to prevent forests from converting to shrubland.
• Reducing tree density through thinning can help build resilience, even under extreme weather conditions.

Original Publication
Authors: Jacob I. Levine, Brandon M. Collins, Michelle Coppoletta and Scott L. Stephens.
Journal: Global Change Biology
DOI: 10.1111/gcb.70400
Method of Research: Observational study
Subject of Research: Not applicable
Article Title: Extreme Weather Magnifies the Effects of Forest Structure on Wildfire, Driving Increased Severity in Industrial Forests
Article Publication Date: 20-Aug-2025
COI Statement: N/A

Original Source: https://attheu.utah.edu/facultystaff/industry-managed-forests-more-likely-to-fuel-megafires/

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