Patch and landscape features drive fire regime in a Brazilian flammable ecosystem

Abstract

The flammable ecosystems are evolutionary dependent on the periodic action of fire. Several environmental factors, both at local and landscape scales, can affect fire regimes in these ecosystems differently. Here, we evaluated the influence of local and landscape features on two parameters of the fire regime of a flammable protected area of the Brazilian savanna: The Chapada Diamantina National Park. We characterized both fire frequency and the time since the last fire, from 1990 to 2019 and measured five environmental predictors (tree canopy cover, altitude, water surface, predominant land use and distance to the nearest municipality). We used Generalized Additive Models for Location, Scale and Shape (GAMLSS) to assess the influence of environmental predictors on the measured fire regime parameters. We found a large interannual variation in the total annual area burned in the studied period. In total, 68 % of the protected area (1030 km2) was burned at least once and 32 % (486 km2) was unaffected by fires during the study period. Predominant land use, distance to the nearest municipality, tree cover and the interaction between tree cover and altitude were negatively related to fire frequency, while the water surface and altitude positively influenced fire frequency in the park. Compared to older fires, recent fires occurred in landscapes at lower altitudes and with lower tree cover. Our results demonstrate that the fire frequency and time since the last fire were highly variable across the park, reflecting the strong influence of landscape heterogeneity on their parameters.