Linkages Between Environmental Attributes and Biotic Integrity in Atlantic Forest Patches

Abstract

Anthropogenic pressures are major drivers of environmental degradation and biodiversity loss worldwide, with forest fragmentation representing one of the most pervasive outcomes of human landuse change. Assessing the biotic integrity of forest patches is therefore essential for supporting biodiversity conservation and restoration planning in fragmented landscapes. However, comprehensive evaluations of ecosystem integrity are often costly and timeconsuming, even when rapid field-based approaches are employed. In this context, remote sensing (RS) has emerged as a complementary tool for characterizing environmental attributes that may influence forest structure and integrity. This study investigated the relationships between environmental variables derived from RS and field-based indicators of forest structure and integrity obtained through a Rapid Ecological Assessment (REA) approach, expressed as a Biotic Integrity Index (BII). Environmental predictors included the Normalized Difference Vegetation Index (NDVI), obtained from an Unmanned Aerial Vehicle (UAV) survey, altitude, distance to the patch edge, and distance to the hydrographic network. Redundancy Analysis (RDA) was applied to explore multivariate associations between environmental and biotic variables. The results revealed statistically significant but weak relationships between the two data domains, indicating limited explanatory power of the selected environmental predictors. Nonetheless, consistent and ecologically coherent patterns were identified, particularly the positive association between BII and mean NDVI and the influence of edge proximity on disturbance-related indicators. These findings highlight both the potential and the limitations of integrating REA with remotely sensed data, emphasizing the complexity of biotic–environmental interactions in fragmented tropical forests and pointing to the need for incorporating additional landscape-scale variables in future studies.