Anthropogenic disturbances have resulted in declines of seed-dispersing primate frugivores in tropical forests. Previous work has suggested that loss of seed dispersal by large frugivores may have a negative impact on ecosystem carbon storage by reducing tree biomass. However, we know little about the potential impacts of losing frugivore loss in Madagascar’s diverse rain forest ecosystem. Understanding the effects of frugivore extinction on carbon loss is relevant in Madagascar where threatened lemur taxa are the only dispersers of many large-seeded plant species. Using a dataset of tree species composition and traits from Ranomafana National Park, we examined whether seed size and lemur-dependent dispersal would be positively associated with above-ground tree biomass. We then simulated different scenarios of population declines of large-seeded trees (> 10 cm seed length) dependent on lemur-mediated seed dispersal, to examine potential directional changes in carbon storage capacity of Malagasy forests under lemur loss.
Results/Conclusions
Lemur-dispersed trees that have large seeds tended to have high above-ground biomass. Our simulations showed that the loss of large frugivorous primates in Madagascar may decrease the forest’s potential to store carbon. These results demonstrate the importance of primate conservation for maintaining functioning ecosystems and forest carbon stocks in one of the world’s hottest hotspots of biodiversity.