Disturbance, Predator, and Resource Interactions Alter Container Community Composition

Species diversity at the local-community scale can be altered by numerous factors, including disturbances, predators, and resource levels. Intermediate levels of these three factors are predicted to enhance coexistence and diversity. However, no study has examined how these factors may interact to alter community composition. The protozoan and rotifer community that colonized containers set in a forest was used to examine the interactions between these local community processes. We conducted a fully factorial microcosm experiment that manipulated disturbance frequency, predator density, and resource levels to examine protozoan and rotifer richness, community composition, and species abundance. Species richness was significantly altered by disturbances and predators, while predator densities interacted with disturbances and resources. Total abundance was significantly affected by each treatment, as well as a disturbance and predator interaction. We found that community composition was altered by each of the treatments and their interactions, indicating that different groups of species were present depending on the treatments. These results indicate that strong species sorting occurs in this community. Understanding these factors alone and in concert can provide insight to the potential complexities that underlie community structure and species composition.