Four-decade analysis of fire behavior in the brazilian Caatinga biome 1985-2023

ABSTRACT Background: The Caatinga, unique in northeastern Brazil, has species adapted to the semi-arid climate. Recurrent fires put its biodiversity at risk, highlighting the need for urgent measures to protect this fragile ecosystem. This study analyzed four decades of fire behavior in the Caatinga biome (1985-2023) using data from the MapBiomas Fire project and spatial analysis, revealing an alarming increase in fire activity, which affected approximately 10.9 million hectares (≈12.74% of the biome). Results: Showed an increasing trend in the frequency and intensity of fires, with critical peaks between August and November, particularly in October where historical maximums were reached in the period 2015-2023 (48.1%). Spatial distribution showed significant concentrations in the western and southern regions of the biome, especially in the states of Bahia and Piauí, mainly linked to human activities. The temporal analysis revealed a progressive accumulation of burned areas, with a notable increase towards the end of the period studied. The recurrence of fires presented a heterogeneous distribution, with up to 39 events at the same point in critical areas, affecting mainly forest formations and herbaceous-bush vegetation. Conclusion: The research underlines the vulnerability of the Caatinga ecosystem to these recurrent events, highlighting the urgent need to implement land management and fire management measures, including continuous monitoring programs and regional adaptive strategies that combine agricultural productivity with ecosystem conservation. This study contributes to the understanding of fire dynamics in tropical semiarid biomes, providing crucial information for decision-making in conservation and sustainable management policies.