When forest loss leads to biodiversity gain: Insights from the Brazilian Atlantic Forest

Abstract

Decades of research indicate that while native habitat loss often drives biodiversity loss and biotic homogenization, there are frequent exceptions. Relying on a multi-level landscape design, multiple biodiversity metrics and species habitat associations we explored one such exception. We investigated dung beetle responses to Atlantic Forest loss by modeling for both specialist and generalist species abundance, alpha and gamma diversities, and beta diversity through a null-model approach (βRC) that permits comparing observed values to those expected by chance. We found that both native forest specialist and habitat generalist communities gained species with native forest loss at local (ᾱ-diversity) and landscape (γ-diversity) levels, while community composition became increasingly dissimilar (β-diversity). Yet, abundance response to forest loss varied between groups. While for generalists, forest loss led to increased overall abundance and abundance distribution across species remained random among communities, for specialists, overall abundance did not change and abundance distribution across species became dissimilar. Such findings suggest that habitat loss does not always drive a decrease in the number of specialist species that compensate for the gain of generalist species, adding to evidence that habitat loss can drive biodiversity gain and biotic differentiation. These responses may be common in particular biogeographical contexts, where contemporary and/or historical regional dynamics may have influenced the resilience of forest biota and contribute to the availability of disturbance-adapted species. Our study highlights the importance of sampling across multiple spatial scales to understand the effects of habitat loss on biodiversity and suggest caution to silver-bullet conservation guidelines.