Conference Agenda

Land use alternations and climate change are shifting natural fire regimes, leading to prolonged and intensified fire seasons accompanied by widespread air pollution, with potentially important consequences for local wildlife. Combining data from the North American Breeding Bird Survey with high-resolution satellite imagery, we estimate the impact of wildfire-specific smoke pollution (PM2.5) on avian biodiversity in the contiguous United States (US) from 2008 to 2022. The panel fixed effects instrumental variable estimation results indicate a short-term adverse effect of PM2.5 on taxonomic and phylogenetic diversity metrics. More specifically, a standard deviation (sd) increase in wildfire-specific PM2.5 pollution reduces species richness, abundance, and phylogenetic diversity by about 0.1 sd, largely driven by observations in the Western US. For the most polluted transects the effect is up to 2-3 standard deviations. Importantly, the adverse effects on biodiversity metrics vary markedly across ecosystems. While the decrease in phylogenetic diversity is most pronounced in the Northwestern Forested Mountains, for the taxonomic metrics it is the Eastern Temperate Forests, the Northern Forests, and the North American Deserts which are driving the adverse effect of wildfire smoke. These findings underscore the need for targeted fire management and conservation strategies to mitigate biodiversity loss, especially in the face of increasing wildfire intensity and smoke exposure projected for many regions worldwide.