Changing Climate, Changing Fire: Understanding Ecosystem-Specific Fire–Climate Dynamics in Arizona and New Mexico

Abstract Wildfire activity in the southwestern United States has intensified in recent decades, driven by the complex interactions of climatic variability, vegetation patterns, and human impacts. This study examines wildfire dynamics in Arizona and New Mexico using data from 1984 to 2021 to evaluate how antecedent moisture and aridity conditions influence fire activity across conifer forests, shrublands, and grasslands. The findings reveal distinct, ecosystem-specific responses to climate: In conifer forests, prolonged drought and rising vapor pressure deficits drive larger and more severe wildfires, underscoring the increasing influence of aridity. In shrublands and grasslands, wildfire risk is often tied to antecedent wet periods that stimulate fine-fuel growth, followed by warm, dry conditions that promote fire spread. The spread of invasive grasses has further heightened fire risk in shrubland and desert ecosystems by enhancing fuel connectivity and transforming fire–climate dynamics in historically fuel-limited regions. As the climate continues to warm and precipitation patterns shift, the spatial and temporal patterns of wildfire activity are expected to remain dynamic, posing significant challenges for fire management and planning. Additionally, the ongoing expansion of the wildland–urban interface will amplify the social and ecological consequences of wildfires, regardless of whether conditions trend wetter or drier. This study highlights the need for adaptive management strategies that incorporate short-term climatic influences into fire-risk assessments while addressing the unique ecological and societal contexts of the region. By advancing understanding of fire–climate–vegetation interactions, this research provides critical insights for mitigating future wildfire impacts in the Southwest.