Truckee, CA (5 September 2025) -- New research finds that treated forests are 88% less susceptible to high severity wildfire than their unmanaged counterparts, and can recover carbon stocks in only 7 years. The findings, carried out by researchers at Vibrant Planet , Northern Arizona University , American Forest Foundation , and Blue Forest , make the case for more proactive forest management across the US, and specifically, the increasingly wildfire-prone West. Read the publication in Frontiers in Forests and Global Change .
Many forests in the West are adapted to live and thrive with frequent, low-severity fire. Yet the confluence of historical fire suppression, intensifying wildfire, and drought, are now rewriting the rules—and the risk—for forests and the communities that live in and around them. This work shows: without human stewardship designed to restore healthy fire regimes and forest structure, many of these fire-adapted forests will go up in flames and may never regenerate, instead transitioning to non-forested ecosystems.
"After 130 years of fire suppression, most of the western US is contending with an enormous wildfire debt " said Katharyn Duffy, a study co-author and Senior Scientist at Vibrant Planet. "It's not a question of if these forests will burn, but when, and where. Every year, we're rolling the wildfire dice. One year, fires land in Arizona and New Mexico; the next, Oregon and Washington. But make no mistake—somewhere in the West, the dice always fall."
As climate-driven megafires and prolonged droughts reshape California's forests, this new peer-reviewed study offers hope—and hard evidence—that proactive forest treatments can tip the scales back toward resilience. The study analyzed over 200 fuel reduction projects across the Central Sierra in California and found that treated forests stored carbon more durably, matching or exceeding untreated areas by year seven—even after the extreme 2020–21 drought and megafires.
The study, which analyzed 216 thinning treatments implemented in California's Central Sierra in 2016 and monitored wildfires that occurred through 2023, found that proactive forest management reduced average wildfire severity by 32% and cut the occurrence of high-severity fire by 88%. Treated areas not only burned less severely but also showed greater stability of live carbon, maintaining or exceeding baseline carbon levels by year seven despite the extreme drought and megafires of 2020–21. Treatments that were larger than six hectares or that received follow-up maintenance, such as prescribed burning or additional fuel removal, delivered the strongest fire-risk reduction and carbon-stabilization benefits.
The researchers focused on California's fire-prone Sierra Nevada region (including portions of the recent Dixie, Caldor, and North Complex megafires) to assess how forest treatments affect wildfire resilience. They compared similar forests—some thinned in 2016, others untouched—creating a natural experiment to track outcomes over five years of drought and wildfires.
The need for a natural experiment approach became apparent as researchers experienced the challenges of capturing recent wildfire impacts. "We started by trying to simulate current wildfire behavior, but we found that models failed to predict the extent and severity of fire conditions in 2020 and 2021," said Ethan Yackulic, the lead author of the study. "For example, the nine largest fires in California's history have all occurred in the past decade. This kind of natural experiment gives us verifiable insights into how forests are truly faring because no model is going to predict what we're witnessing right now."
Yackulic explains, "even though the treatments we monitored had a high initial 'carbon cost' in the removal of live trees, a dramatic signal of forest resilience emerged in subsequent years. While other studies have shown that management interventions are effective at reducing wildfire hazard risk on a treatment-by-treatment basis, it was encouraging to witness landscape scale treatment effectiveness and the potential for more durable carbon storage across the Central Sierra Nevada."
Sophie Gilbert, a study co-author and Director of Science Strategy at Vibrant Planet, said these results help answer one of the central questions facing land managers today: "How much treatment would we have to do, how intensely, and where, to reduce a forest's risk to severe fire, and drought?" Gilbert said part of that answer is not just calibrating intensity of fuel treatments but committing to a sustainable relationship with the land.
These results could support an additional source of funding for forest restoration and management efforts, recent research from Blue Forest suggests, while keeping forests and their many ecosystem benefits intact. "Treating forests is about re-establishing humans' reciprocal relationship with the land. It requires sustained attention and effort. And in return, forests will reward us with abundant ecosystem services. One of these is keeping carbon out of the atmosphere, but so many others come along for the ride: water quality and quantity, biodiversity, and more." said Gilbert.
