Getting to the facts about impacts of high-severity wildfires

Reviewing the science behind wildfire management

All the work being done by the League and its partners in the giant sequoia range to protect the forests from high-severity wildfires is based on the broad consensus of scientific research. Nonetheless, a great deal of confusion exists in the media and elsewhere about both the threat that high-severity fire presents and what, if anything, should be done about it. We share the following statements of fact, along with citations from academic research, in the hope of dispelling misconceptions.

The following is adapted, with permission, from Counteracting Wildfire Misinformation, published in the September 2022 issue of Frontiers in Ecology and the Environment by Gavin M. Jones, Emily K. Vraga, Paul F. Hessburg, Matthew D. Hurteau, Craig D. Allen, Robert E. Keane, Thomas A. Spies, Malcolm P. North, Brandon M. Collins, Mark A. Finney, Jamie M. Lydersen, and A. Leroy Westerling. (Full citations to referenced studies are at the bottom of the page)

Contemporary wildfires are not normal

Contemporary wildfires are abnormal in many ecosystems; those burning in seasonally dry forests are far outside the historical range of variation because of >100 years of fire suppression (leading to buildup and increased landscape continuity of fuels) and climate change, generally burning at a higher severity, in larger patches, and over larger areas.

Forests will not always naturally recover from high-severity wildfires

Without intervention, many forests will convert to non-forest due to disturbances and climatic warming, unable to naturally recover after high- intensity fires due to inadequate conifer seed availability, failed conifer regeneration, worsening site climate, elevated fuel loads and connectivity from fire exclusion, cyclic reburning, and post-fire dominance of shrubs and grasses. Under rapid climate change, natural recovery processes cannot maintain natural fire and ecosystem processes; appropriate interventions can make many forests more resilient to the effects of climate change or incrementally facilitate some inevitable transitions to non-forest.

Fuels reduction treatments are proven to work

There is abundant evidence that forest fuel treatments work, particularly those using fire itself, whether prescribed or managed. Such treatments moderate the behaviors of wildfires, even under extreme weather, slowing their spread, lowering fireline intensity, and reducing severity and smoke production in treated areas. Fuel treatments are appropriate in systems that were historically fuel-limited, and in those high severity systems that currently lack typical burned and recovering patchworks of forest and non-forest.

Fuels reduction is not a Trojan horse for commercial logging

Mechanical fuels reduction focuses on retaining medium and large-sized fire-tolerant trees, to foster their survival of the next fire. Fuels reduction treatments restructure and remove woody material and fuel ladders that built up during fire exclusion, and are often of limited economic value. In other cases, removal of medium-, or large-sized fire-intolerant trees that recruited during fire exclusion is essential to improve fire-tolerant tree survival. The catchphrase “fuels reduction logging” deceptively conflates two very different types of forest management.

Contemporary high-severity wildfires are not beneficial to wildlife

Changing fire regimes pose serious threats to the persistence of numerous native wildlife populations. The massive scale of stand-replacing patches typifying contemporary “megafires” homogenizes landscapes, reduces overall faunal species richness, and eliminates critical habitat for even fire-dependent forest species. Forest wildlife require the long-term persistence of a substantially forested landscape mosaic, as it adapts to climate change and the variability of the fire regime that emerges.

Referenced studies: