Are neotropical cave-bats good landscape integrity indicators? Some clues when exploring the cross-scale interactions between underground and above-ground ecosystems

Abstract

Neotropical caves located in pristine ecosystems harbor high biodiversity but face functional shifts and degradation interlinked with aboveground changes. Cave-roosting bats have been proposed as integrity indicators of karst landscapes considering their sensitive to both the underground and aboveground characteristics and resources. In the present study, the selection of caves by bats in karst areas across a landscape gradient in the Brazilian Amazon was investigated. We envisioned that taxonomic and guild diversity should respond dissimilarly to disturbance at different scales, namely by a selective offsetting of the bat community. To test our hypothesis, we accordingly selected caves spanning a gradient of disturbance, located in old growth forests, secondary forests, forest fragments, agricultural landscapes, and pastures. Species and traits showing responses to the gradient of caves and aboveground ecosystems were identified. On the basis of patterns of occurrence, we determined those communities unique to or primarily associated with undisturbed caves located in pristine ecosystems and landscapes. Disturbed caves, which are generally located in areas of agriculture and pastures, were found to have detrimental effects on specialized species and functional guilds diversity. Our preliminary results reveal that bat communities are particularly sensitive to gradients of cave and ecosystem disturbance, and consequently might add ecological information to the currently used indicators for assessing the ecological status of landscapes in the Neotropics.