Multitrophic richness enhances ecosystem multifunctionality of tropical shallow lakes

1. Biodiversity provides multiple functions and services to ecosystems. However, the role of biodiversity in sustaining multiple functions simultaneously (multifunctionality) is still poorly understood in natural communities, especially in hyperdiverse tropical freshwater ecosystems. Studies have focused on the effect of single trophic groups on ecosystem function and on individual ecosystem functions.

2. Using a 16-year database from tropical shallow lakes, we combined species richness of nine trophic groups into a unique measurement of multitrophic richness. We then investigated the influence of the richness within separate trophic groups and in a multitrophic context on ecosystem multifunctionality. We also analyzed how the interactions among multiple trophic groups affect multifunctionality.

3. The multitrophic richness had a stronger positive effect on multifunctionality than the richness of single trophic groups. The removal of each trophic groups decreased the effect of the multitrophic richness on multifunctionality. The larger predatory vertebrates and primary producers had stronger positive effects on multifunctionality, but the richness of basal trophic groups fueled the large size predators, thus indirectly contributing to increase multifunctionality.

4. Our study has important implications for conservation, such as the need for preserving multiple trophic groups to maintain multifunctional integrity in natural freshwater ecosystems. Moreover, trophic simplification (loss of trophic groups) of the ecosystems should strongly impair their functioning.