Relative fire-proneness of land cover types in the Brazilian Atlantic Forest

Abstract

Fires have long posed a global problem, but they are now increasingly affecting tropical biomes where landscape-fire interactions remain understudied. We investigate the fire-proneness of different land use and land cover types (LULCs) within the Brazilian Atlantic Forest (AF), one of the world's most important biodiversity hotspots, experiencing increased fire frequency due to human activities and climate change. Using a selection ratio-based approach, we analyzed fire-LULC interactions in 40,128 fires over a 35-year period (1987-2022) across various vegetational regions in the AF, evaluating the relative fire-proneness of different LULCs in a tropical biome for the first time. Our findings revealed that secondary forests, forest areas that have regrown after major disturbances, burned 61% more than expected by chance, whereas old-growth forests, native forests that have developed over very long periods, burned 57% less than expected, highlighting a nearly inverse relationship in their fire-proneness. Interestingly, our data indicate that pastures in the AF are less prone to fire than expected, despite being considered among the land uses that burn the most in Brazil. Other LULCs showed variable fire-proneness, with some differences between vegetational regions. Over time, the fire-proneness of secondary forests decreased, likely due to forest maturation and changes in land management practices. We emphasize the necessity for tailored fire management strategies that address the unique vulnerabilities of secondary forests, particularly in the context of ongoing restoration efforts aimed at increasing native forests. Effective measures, including the implementation of fire-smart management practices and enhancing the perceived value of secondary forests among local communities, are crucial for mitigating fire risks. Integrating these strategies with incentive-based approaches can bolster fire prevention, ensuring the long-term success of restoration programs. Our study provides a framework for understanding fire-landscape dynamics in tropical forests and offers actionable insights for practitioners working to safeguard these biomes from the escalating threat of wildfires.