Guild-Specific Frog Responses to Natural Habitat Structure Gradients in an Atlantic Forest Mosaic

Abstract

Habitat heterogeneity is widely considered a key driver of biodiversity, yet empirical evidence remains uneven across taxonomic groups and ecological contexts. Here, we evaluate how habitat structure gradients are associated with frog species richness and occupancy in a heterogeneous mosaic of the Atlantic Forest. Using data collected over 3 years and applying a multi-species, multi-season occupancy modeling framework, we tested whether habitat structure gradients were associated with richness and occupancy patterns across ecological guilds. Overall, we observed a negative trend in community-level occupancy with increasing values of the habitat structure gradient. When responses were analyzed by ecological guild, arboreal species showed neutral or positive associations, while cryptic and terrestrial species exhibited more negative associations. Estimated species richness was highest in sites associated with lower values of the habitat structure gradient, with richness decreasing toward higher gradient values. These simpler habitats, however, were not ecologically degraded but contained key resources such as bromeliads and temporary ponds, which are important for reproduction for many frog species. Because the habitat gradient incorporated both vegetation structure and habitat resources, the observed patterns likely reflect the combined influence of habitat structure and resource distribution. Our results indicate that habitat gradients may differentially favor distinct ecological strategies across frog guilds. These findings highlight that relationships between habitat structure and biodiversity can be context-dependent and underscore the need for more nuanced conservation planning. Managing habitat mosaics that support diverse ecological requirements may be more effective than maximizing vegetation complexity alone in tropical forest ecosystems.