Niche measures and growth rate do not predict interspecific variation in spatial synchrony of phytoplankton

Spatial synchrony occurs when local populations exhibit correlated dynamics over time. Recent studies, both experimental and observational, have indicated that the magnitude of spatial synchrony, in cross-species analyses, is correlated with the level of specialization. In theory, specialist species would exhibit higher levels of synchrony than generalist species because they would be more sensitive to environmental variations. In addition, according to simulation studies, species with high growth rates should have more synchronized dynamics. In this study, we tested these hypotheses using datasets (phytoplankton populations and environmental variables) obtained in the Cana Brava Reservoir (State of Goiás, Brazil). We used a multiple regression model to test whether the average level of spatial synchrony was correlated with variables that indicate environmental specialization and population growth rate. In general, the average values of spatial synchrony were low, indicating the predominance of local factors in controlling population dynamics. We found no significant relationship between synchrony and our explanatory variables. To assess the generality of correlates of spatial synchrony, we suggest that future studies should focus on a common same set of explanatory variables.