Continued warming could transform Greater Yellowstone fire regimes by mid-21st century

Abstract

Climate change is likely to alter wildfire regimes, but the magnitude and timing of potential climate-driven changes in regional fire regimes are not well understood. We considered how the occurrence, size, and spatial location of large fires might respond to climate projections in the Greater Yellowstone ecosystem (GYE) (Wyoming), a large wildland ecosystem dominated by conifer forests and characterized by infrequent, high-severity fire. We developed a suite of statistical models that related monthly climate data to the occurrence and size of fires >200 ha in the northern Rocky Mountains; these models were cross-validated and then used with downscaled (∼12 km × 12 km) climate projections from three global climate models to predict fire occurrence and area burned in the GYE through 2099. All models predicted substantial increases in fire by midcentury, with fire rotation (the time to burn an area equal to the landscape area) reduced to <30 y from the historical 100-300 y for most of the GYE. Years without large fires were common historically but are expected to become rare as annual area burned and the frequency of regionally synchronous fires increase. Our findings suggest a shift to novel fire-climatevegetation relationships in Greater Yellowstone by midcentury because fire frequency and extent would be inconsistent with persistence of the current suite of conifer species. The predicted new fire regime would transform the flora, fauna, and ecosystem processes in this landscape and may indicate similar changes for other subalpine forests.

Impact of anthropogenic climate change on wildfire across western US forests

“…Although numerous studies have projected changes in burned area over the twenty-first century due to ACC, we are unaware of other studies that have attempted to quantify the contribution of ACC to recent forested burned area over the western United States. The near doubling of forested burned area we attribute to ACC exceeds changes in burned area projected by some modeling efforts to occur by the mid-twentyfirst century (29,30), but is proportionally consistent with midtwenty-first century increases in burned area projected by other modeling efforts (17,(31)(32)(33).…”

“…The growing ACC influence on fuel aridity is projected to increasingly promote wildfire potential across western US forests in the coming decades and pose threats to ecosystems, the carbon budget, human health, and fire suppression budgets (13,48) that will collectively encourage the development of fire-resilient landscapes (49). Although fuel limitations are likely to eventually arise due to increased fire activity (17), this process has not yet substantially disrupted the relationship between western US forest fire area and aridity. We expect anthropogenic climate change and associated increases in fuel aridity to impose an increasingly dominant and detectable effect on western US forest fire area in the coming decades while fuels remain abundant.…”

“…The strong interannual correlation between forest fire activity and fire-season fuel aridity, as well as observed increases in vapor pressure deficit (VPD) (9), fire danger indices (10), and climatic water deficit (CWD) (11) over the past several decades, present a compelling argument that climate change has contributed to the recent increases in fire activity. Previous studies have implicated anthropogenic climate change (ACC) as a contributor to observed and projected increases in fire activity globally and in the western United States (12)(13)(14)(15)(16)(17)(18)(19), yet no studies have quantified the degree to which ACC has contributed to observed increases in fire activity in western US forests.…”

Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies

“…Bark beetle outbreaks and wildfire occurrence are both predicted to increase with continued climate warming in North America (7,46) and worldwide (11). The effects of each may be individually severe, but we found recent MPB outbreaks affected few measures of subsequent wildfire severity in subalpine forests in multiple wildfires across a large (∼50,000 km 2 ) region of the Northern US Rockies.…”

Frequência espaço-temporal dos focos ativos em Minas Gerais durante o período de 1999 a 2009

“…Os incêndios florestais também podem acelerar os processos de mudanças climáticas (WESTERLINGA et al, 2011) pela emissão de gases de efeito estufa na atmosfera. Os incêndios devem ser prevenidos por meio de uma gestão eficaz.…”