FATORES LOCAIS DETERMINAM A AUSÊNCIA DE SINCRONIA DO ZOOPLÂNCTON EM UM RESERVATÓRIO TROPICAL

Abstract

Spatial synchrony studies contribute to understanding population dynamics over time. Zooplankton communities are excellent models for synchrony studies, especially in lakes, where high connectivity is expected. We studied the Spatial synchrony of these organisms in the reservoir of the Serra do Facão Hydroelectric Power Plant, located on the São Marcos River in the Alto Paranaíba Basin, southeast Goiás, and its correlation with matrices of limnological, climatological and operational variables of the reservoir, and a Euclidean matrix of geographical distance. To this end, data from 10 sampling points, a climatological station and operational data from the website of the National Water and Sanitation Agency (ANA), collected during the years 2016 to 2022, summarized by a principal component analysis (PCAs) before the matrices were generated by estimating Spearman's correlation coefficients. Finally, the biological synchrony matrix was correlated with the other matrices using the Mantel test. Synchroni was not significant for any taxa. All the taxa showed lack of synchrony. We also found that dispersal was not important. The most abundant taxa (groups, genera and species) were correlated with the physical limnological and productivity variables, especially the Copepoda and Cladocera groups, indicating the existence of a compensatory dynamic in the system, where local factors (i.e. anthropogenic) are preponderant in the occurrence of absencespatial synchrony. Corroborating this, we found that the low variation in non-cyclical operational data can act as a regionalized factor independent of density, limiting the effects of climate on synchrony. The knowledge acquired in this study will be important for evaluating decisions regarding possible impacts on the reservoir in question, including the need to revise the sampling mesh, it will also serve as a source of information for studies in other reservoirs.