Contemporary fires are less frequent but more severe in dry conifer forests of the southwestern United States
Year: 2024
Type: article
Abstract: Wildfires in the southwestern United States are increasingly frequent and severe, but whether these trends exceed historical norms remains contested. Here we combine dendroecological records, satellite-derived burn severity, and field measured tree mortality to compare historical (1700-1880) and contemporary (1985-2020) fire regimes at tree-ring fire-scar sites in Arizona and New Mexico. We found that contemporary fire frequency, including recent, record fire years, is still <20% of historical levels. Since 1985, the fire return interval averages 58.8 years, compared to 11.4 years before 1880. Fire severity, however, has increased. At sites where trees historically survived many fires over centuries, 42% of recent fires resulted in high tree mortality. Suppressed wildfires tended to burn more severely than prescribed burns and wildfires managed for resource benefit. These findings suggest that expanded use of low-severity prescribed and managed fire would help restore forest resilience and historical fire regimes in dry conifer forests.
Institutions: National Park Service, Western Colorado University, National Oceanic and Atmospheric Administration, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, NOAA National Centers for Environmental Information, United States Geological Survey, Fort Collins Science Center, US Forest Service, Rocky Mountain Research Station
Language: English
Topic: Fire effects on ecosystems
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDGs: Life on land, Climate action
Open Access status: gold
Estimated APC paid: $3,290
OpenAlex ID: W4403316297