Climate influences on future fire severity: a synthesis of climate-fire interactions and impacts on fire regimes, high-severity fire, and forests in the western United States

Abstract

Background Increases in fire activity and changes in fire regimes have been documented in recent decades across the western United States. Climate change is expected to continue to exacerbate impacts to forested ecosystems by increasing the frequency, size, and severity of wildfires across the western United States (US). Warming temperatures and shifting precipitation patterns are altering western landscapes and making them more susceptible to high-severity fire. Increases in large patches of high-severity fire can result in significant impacts to landscape processes and ecosystem function and changes to vegetation structure and composition. In this synthesis, we examine the predicted climatic influence on fire regimes and discuss the impacts on fire severity, vegetation dynamics, and the interactions between fire, vegetation, and climate. We describe predicted changes, impacts, and risks related to fire with climate change and discuss how management options may mitigate some impacts of predicted fire severity, and moderate some impacts to forests, carbon, and vegetation changes post fire. Results Climate change is increasing fire size, fire severity, and driving larger patches of high-severity fire. Many regions are predicted to experience an increase in fire severity where conditions are hotter and drier and changes in fire regimes are evident. Increased temperatures, drought conditions, fuels, and weather are important drivers of fire severity. Recent increases in fire severity are attributed to changes in climatic water deficit (CMD), vapor pressure deficit (VPD), evapotranspiration (ET), and fuels. Fire weather and vegetation species composition also influence fire severity. Future increases in fire severity are likely to impact forest resilience and increase the probability of forest type conversions in many ecosystems. Conclusions Increasing warming and drying trends are likely to cause more frequent and severe disturbances in many forested ecosystems in the near future. Large patches of high-severity fire have lasting legacies on vegetation composition and structure, and impacts on tree regeneration. In some ecosystems and under certain fire-weather conditions, restoration and fuel treatments may reduce the area burned at high severity and reduce conversions from forest to non-forest conditions, increasing forest resistance and resilience to wildland fire. Thinning and prescribed fire treatments can be effective at reducing the potential for crown fire, reducing fuels, and promoting forest resilience.

A Preliminary Case Study on the Compounding Effects of Local Emissions and Upstream Wildfires on Urban Air Pollution

“…Childs et al [18] found that in the last ten years, daily fine particulate matter (PM 2.5 ) concentrations from smoke have risen by up to 5 µg m −3 in the Western US. Abatzoglou et al [19] also found that interannual variations in area burned in the Western US are strongly positively correlated with climactic warming and drying, with large increases in acres burned by wildland fires since 1980, and these trends are expected to continue [20]. Local ozone photochemistry (titration) during smoky conditions in urban environments primarily depends on the amount of available nitrogen oxides (NO x ), as large concentrations of VOCs are typically transported with the smoke plume [21].…”

How do invasive predators and their native prey respond to prescribed fire?

“…Climate change is likely to continue to intensify the effects of fire in many forested areas globally, by potentially leading to more frequent, large, and/or severe wildfires (Canadell et al., 2021; Jones et al., 2022; Wasserman & Mueller, 2023). This trend is likely to be paralleled by a rise in the use of prescribed fires in an effort to mitigate the escalating threat to human life and infrastructure posed by these intensified wildfire events (Kolden, 2019; Varner et al., 2021).…”

Research advances in Graphic and Design Engineering at the UPC BarcelonaTech

“…El impacto creciente del cambio climático ha incrementado la frecuencia y severidad de los incendios forestales, lo que representa un riesgo significativo para los ecosistemas y comunidades, haciendo imprescindibles sistemas de detección temprana eficientes (Wasserman & Mueller, 2023). Dichos sistemas son claves para alcanzar unos Objetivos de Desarrollo Sostenible de la ONU, especialmente aquellos enfocados en la acción climática (Carta, Zidda, Putzu, Loru, Anedda & Giusto, 2023;Robinne, 2021).…”