LAUSR

Different processes, including ecological drift, environmental changes, and biotic homogenization, can explain variation in temporal beta diversity. Here, we aimed to analyze the temporal beta diversity of zooplankton communities along the longitudinal axis of a reservoir using two analytical approaches. As for the first approach, we predicted that that beta diversity would be positively correlated with limnological variability. We used multiple samples-based metrics to estimate beta diversity among 62 sampling months at six sampling sites; after, we correlated these metrics with within-site temporal variability in limnological factors. As for the second approach, we predicted that between-months variation in community composition would be positively correlated with time lags and between-months environmental distances. Considering the multiple samples approach, we did not detect a significant relationship between temporal beta diversity and variability in limnological factors. Between-months beta diversity was unrelated to between-months differences in limnological and hydrological factors. Only temporal lags were significantly correlated with between-months beta diversity. Beta diversity and species richness were substantially highest at the lotic zone of the reservoir. Our results indicate that temporal beta diversity tends to be highly unpredictable and that most of the taxa contributing to the regional diversity of the reservoir disperse via its lotic region.