Influence of fire on edge vegetation in an Atlantic Forest remnant in Brazil

Abstract

Fires and habitat fragmentation are responsible for devastating large ecosystems around the biosphere. The increasing use of remote sensing allows fire patterns to be identified and plays an essential role in preventing fires. In this context, this study aimed to describe the variation in evidence of fire between the edge and the interior of an Atlantic Forest remnant in southeastern Brazil and infer its effects on vegetation. Fire records were acquired between 2010 and 2020 from the Instituto Nacional de Pesquisas Espaciais database and United States Geological Survey satellite images. For each scene, the images were processed and the normalized difference vegetation index (NDVI) was calculated. To assess the variation, records were classified and compared according to the year, month, hours, and habitat type (edge and interior). To verify the influence of fires on vegetation, simple linear regressions were performed based on the fire risk due to the NDVI-year-habitat interaction. The data included 748 fire records, with the highest occurrences from April to August, and 51% of the fires occurred between 15h and 20h, indicating periods with more intense solar radiation. The relationship between fire risk and NDVI-year-habitat was significant (F = 30.35; R 2 = 0.26; p < 0.0001), and the edges were more vulnerable to fire risk. This study shows that in an Atlantic Forest remnant, areas with lower vegetation indices, such as edges, are more vulnerable to fire than areas with dense forest vegetation. queimadas ocorreram entre 15h e 20h, indicando períodos de radiação solar mais intensa. A relação entre risco de fogo e NDVI-ano-habitat foi significativa (F = 30,35; R2 = 0,26; p < 0,0001), e as bordas, como esperado, foram mais vulneráveis ao risco de fogo. Este estudo mostra que em um remanescente de Mata Atlântica, áreas com índices de vegetação mais baixos, como bordas, são mais vulneráveis ao fogo do que áreas com vegetação florestal densa.