Forest loss and isolation effects on mutualistic plant-bat interactions in a Neotropical savanna

Human-induced habitat loss and isolation have severe impacts on biodiversity, with indirect effects on plant-animal interactions. We investigate how forest loss and isolation (distance) from a large continuous forest affect mutualistic plant-bat interaction networks based on a seven-years survey across 20 sites surrounding the Serra da Bodoquena National Park, Brazil. Our results showed that landscapes with 30–70 % forest cover at 1 km-radius buffer had more species (9 bat species: r² = 0.50, p = 0.01; 24 plant species: r² = 0.54, p = 0.001) and interactions than those at the extremes, either heavily deforested or fully forested landscapes. Plant-bat networks were also larger and more modular (0.60), with lower connectivity (0.18), in landscapes with intermediate than in extremes forest cover values (r² = 0.51, p = 0.03; r² = 0.73, p = 0.002; respectively). Richness of interacting bats (9 species) and network modularity (0.60) were higher at 10 km from the park’s continuous forest than in sites closer or further away (r² = 0.39, p = 0.05; r² = 0.54, p = 0.002; respectively). Overall results indicate that forest loss and isolation from the park nonlinearly affect the size and structure of plant-bat networks, with intermediate levels of forest cover and isolation supporting larger and more modular networks. These outcomes highlight the importance of keeping a considerable area of forest remnants in human-modified landscapes, and the crucial role of large protected forests to maintain pollination and seed-dispersal plant-bat interactions.