Priority caves for biodiversity conservation in a key karst area of Brazil: comparing the applicability of cave conservation indices

Landscapes in tropical regions have been greatly altered by human activities, as a product of growing demands for mineral and agricultural production, as well as those related to the generation of energy (e.g., hydroelectric, wind). In this scenario, caves have suffered several impacts, sometimes irreversible, as they are generally associated with rocks of high economic value and are closely related to epigean systems. Several indices have been proposed to guide conservation policies for the world’s speleological heritage, although few of them consider cave biodiversity as a criterion. To address this knowledge gap, we tested the applicability of four newly proposed indices to assist researchers and policy-makers select priority areas for global cave biodiversity conservation. To compare indices, we used data from 48 caves of the largest carbonate region of South America (Bambui geological group), all found within the Cerrado, a global biodiversity hotspot. Each of the four indices considered cave biodiversity as a criterion, although only three adequately evaluated this attribute. Based on results of Simões index and CCPi, which were the most appropriate in relation to indicate priority caves for biodiversity conservation in regions where the fauna and its distribution are not fully known, 15 of the 48 caves were identified as conservation priorities.