Fruit bat diversity patterns for assessing restoration success in reforestation areas in the Philippines

Abstract

In response to extensive deforestation in the Philippines in the last century, reforestation initiatives have been developed, setting area- or seedling count-based success criteria. However, to sufficiently assess reforestation as an approach to conserving biodiversity and protecting habitats, restoration of ecosystem integrity must be evaluated. Increased recognition of the role of fauna in ecological restoration has led to the evaluation of the role of different groups in assisting recovery and as potential metrics of success. In this study, we used mist netting data to evaluate how richness, abundance, diversity, and composition of fruit bats differ between reforestation areas and nearby secondary forest, and their potential as measures of restoration success. We captured 6564 fruit bats representing 15 species from a sampling effort of 1,994,366 m2·h. Estimated species richness and Simpson indices did not differ significantly between habitat types. Overall abundance was only significantly different in Palinpinon, with more individuals in the reforestation area, while Shannon indices only differed significantly in BacMan. Differences in composition were all found to be statistically significant, based on non-metric multidimensional scaling ordination biplots and permutational MANOVA. Of the three most abundant species captured across all reservations, the generalists Cynopterus luzoniensis and Macroglossus minimus were more abundant in reforestation areas. On the other hand, the forest specialists Haplonycteris fischeri, Harpyionycteris whiteheadi, and Ptenochirus minor showed lower abundances in reforestation areas. While univariate biodiversity metrics did not differ between secondary forests and reforestation areas, the abundance of particular species and the species composition of fruit bats remained distinct between these habitats. We identified specific aspects of the fruit bat assemblage with the potential as metrics of restoration success. To facilitate evaluation of restoration success using changes in faunal assemblage, we recommend the development of sampling protocols and metrics that would standardize this process.