Natural ecosystem loss in an Atlantic Forest agricultural basin: drivers of land-use change and future landscape trajectories

Abstract

The Atlantic Forest, one of the world's most threatened biodiversity hotspots, faces intense pressure from agricultural expansion and inadequate land governance. Understanding the spatial drivers and future trajectories of land-use and land cover (LULC) change is critical for safeguarding the ecosystem services and biodiversity that remnant natural areas provide. This study investigated the relative importance of multiple biophysical, socioeconomic, and demographic drivers of natural ecosystem loss in the Guaporé River Basin (GRB), a 246,300-ha subtropical Atlantic Forest agricultural watershed in southern Brazil. We combined a municipality-level temporal trend analysis to characterize historical LULC dynamics (1998–2019) with the Dinamica EGO cellular automata model, calibrated using Weight of Evidence (WoE), to simulate future landscapes under 2030 and 2050 scenarios. Our results reveal divergent ecological dynamics across the basin. The Northern region experienced extensive remnant vegetation loss (1.55% yr −1 conversion to altered ecosystems), driven by flat terrain and high agricultural productivity, while the Southern region showed partial natural regeneration (1.40% yr −1 transition from altered to regenerating vegetation), linked to steeper slopes and vegetation extraction practices. Despite apparent recovery, closer analysis reveals a regressive process of ecological simplification, in which remnant vegetation is progressively replaced by regenerating vegetation. Future projections suggest that, without strengthened enforcement of Brazil's Natural Vegetation Protection Law, the Northern basin will lose an additional 15,903 ha of remnant vegetation by 2050. These findings highlight critical spatial mismatches between legal protection frameworks and actual land-use pressures, with direct implications for conservation planning, watershed management, and biodiversity protection in the Atlantic Forest biome.