Fire dynamics in extreme climatic events in western amazon

Abstract

This study aimed to evaluate fire dynamics in ‘extreme’ climatic events of the El Niño Southern Oscillation in the western Amazon in Acre, Brazil. It employed remote sensing products of burned areas, the Enhanced Vegetation Index (EVI), rainfall products, and kernel density to spatialise fire foci. The largest burned area recorded during the study was during the La Niña period, with a total of 296 km2 burned. The highest concentration of fire foci was found in the lowland open ombrophilous forest in areas with palm trees, where 28% of the fires occurred. Rainfall was concentrated on the cover of the submontane dense ombrophilous forests with emergent canopies with a maximum value of 2515.9 mm in the La Niña event. The highest and lowest EVI values occurred in the neutral episode with values ranging from 0.57 to 0.36. The correlation between burned and fire foci areas was greatest during the El Nino period (0.92). On the other hand, the maximum negative value was found between the rainfall and fires in the neutral episode (−0.80). Fire outbreaks and EVI presented a significant positive growth trend in the neutral episode. The largest fires were recorded during the neutral period, and this study highlights the vulnerability of the western Amazon to fire.