Positive effects of surrounding rainforest on composition, diversity and late-successional seed dispersal by bats

Abstract

The configuration of a heterogeneous landscape has an important effect on species composition and landscape processes. The importance of the size, shape and habitat suitability of forest patches has been widely studied, but there is increasing evidence that the spatial context, e.g. adjacency or contact between two landscape elements, can have positive effects on ecological interactions, such as the movement of frugivorous bat species and seed dispersal. We compared the composition, diversity and richness of seed species transported by bats in rainforests and in secondary forests that were either partially or largely surrounded by rainforest, in relation to the fruit species’ life form and successional stage. To capture frugivorous bats we used mist nets with a plastic sheet placed below to allow dropped fruit and seeds from bat feces to be retrieved. Similar species composition and the highest diversity of transported seeds were found in rainforest and secondary forest largely surrounded by rainforest, while the highest number of seed species was recorded in rainforest and secondary forest partially surrounded by rainforest. More bats were captured transporting late-successional stage seeds in secondary forest largely surrounded by rainforest. This study demonstrates the importance of rainforest surrounding secondary forests to bat species’ movement and its positive effect on diversity and late-successional seed dispersal by bats. Maintaining large areas of rainforest around secondary forests is a useful management strategy for supporting high bat species diversity and abundance, and positively affects the transportation and potential dispersal of seed species of different successional stages.