Multidimensional diversity assessment of cave-associated bats in Brazil reveals major conservation gaps

Abstract Cave-associated bats share unique ecological traits and are often highly vulnerable, yet their diversity patterns remain poorly understood at large spatial scales. We provide the first national-scale assessment integrating taxonomic (TD), phylogenetic (PD), and functional diversity (FD) for cave-associated bats in Brazil. Using species range maps, trait-based metrics, and molecular phylogeny, we calculated diversity within 10 km × 10 km grid cells (n = 72,180) and assessed spatial overlap with land-use pressures and protected areas. At the national scale, Caatinga and Amazon showed the highest concentrations of TD and PD, though patterns varied by threshold level. FD showed contrasting patterns: broad coverage at lower thresholds but highly restricted high-diversity areas at the highest thresholds, mainly in the Atlantic Forest, Cerrado, and Caatinga. Biome-specific thresholds revealed additional diversity patterns, including hidden TD, PD, and FD within the Pampa and Pantanal, identifying important regional conservation priorities that national thresholds overlooked. Overlap analyses showed that extensive high-diversity areas coincided with ongoing land-use pressures, especially agriculture and mining, concentrated in the Amazon, Cerrado, Atlantic Forest, and Caatinga. Protection was limited and uneven: at the ≥ 90% threshold, only 23% TD, 27% PD, and 33% FD grid cells overlapped with protected areas. Biome-specific thresholds modestly improved estimated protection for TD and PD but exposed gaps in functionally unique areas. Cave-associated bat diversity in Brazil exhibits complex, scale-dependent spatial patterns, and the widespread mismatch among biodiversity value, land-use pressure, and protection underscores the urgent need for biome-sensitive, multidimensional conservation planning.