Dispersal ability and niche breadth act synergistically to determine zooplankton but not phytoplankton metacommunity structure

Abstract It is well known that both niche requirements and dispersal act together to structure communities; however, it remains unclear how the underlying mechanisms create the observed patterns in nature. In plankton communities, traits related to dispersal ability (e.g. body and propagule sizes) and niche breadth (i.e. habitat generalists and habitat specialists) have recently shown promise in this regard. Here, we hypothesized that body size (a proxy for dispersal ability) and niche breadth act together to determine limnetic plankton metacommunity structure in a tropical system of natural landlocked lakes in Brazil. Our hypotheses were partially supported for zooplankton community. Copepoda showed no relation to environmental variables, and the larger-bodied Calanoida was structured only by space. The Cladocera showed the largest spatial and environmental limitation. Rotifers showed the lowest association with space; however, its pure environmental fraction was higher than expected. The phytoplankton community was largely structured by both environment and space. The spatial limitation of this group was a clear divergence from our expectations. Lastly, we revealed that intragroup variation (when species were evaluated individually) was equal or larger than between group variation, indicating that group-specific traits may play a more important role in determining metacommunity structure.