A influência de características da paisagem na dinâmica de incêndios florestais na Mata Atlântica costeira da Bahia

Abstract

The Brazilian Atlantic Forest is currently highly degraded and fragmented, with only 28% of its original vegetation cover. Fires are one of the factors that influence increasing deforestation, due to climate change and the growing anthropogenic impact on natural environments. However, unlike some other biomes, the Atlantic Forest vegetation does not have the necessary adaptations for fire occurrence, so fire impacts are more intense. Furthermore, landscape characteristics such as road density, percentage of vegetation cover, edge density, presence of pasture areas and protected areas have the potential to influence the dynamics of wildfires. Thus, the aim of this study was to evaluate the relationship between the space-time dynamics of fire and the structure of landscapes located in the coastal Atlantic Forest of the state of Bahia. Therefore, we present general characteristics of a 35-year history of the region's landscapes, based on remote sensing data obtained from MapBiomas and analyzes of how these characteristics influence the occurrence, frequency of fire, extension and proportion of burned areas. Overall, we observed a pattern of decreasing fire occurrence and frequency, however, during the last 5 years we identified the opposite pattern. In landscapes occupied by pasture and vegetation with high to intermediate coverage and high border density, we identified a greater relationship with the increase of fire occurrence and the extent of burned areas. Landscapes with a higher density of roads were indicative of a higher occurrence of fire. Proportionately to the amount of vegetation in the landscape, areas with greater vegetation cover had fewer fire foci. Only during the last 10 years (2010 to 2020) there was a diminishing pattern of fire occurrence in landscapes, due to the presence of Sustainable Use Conservation Units, mainly due to the Private Natural Heritage Reserves (RPPNs) created during that period. Therefore, the study made it possible to spatially identify the largest wildfires in the Atlantic Forest of Bahia, a pattern of fire reduction during the 35 years analyzed, and relations of fire increase in landscapes characterized by a greater amount of pasture, borders and roads, and less proportion of vegetation. In this sense, we recommend conservation and restoration actions for the biome, focused on fire inspection and management and creation of new protected areas for the region, together with improvements on infrastructure and management of the established ones.