Climate affects the structure of mixed rain forest in southern sector of Atlantic domain in Brazil

•Geomorphological surface affects climate and, thereby, the structure of vegetation.•There were a major effect of thermal variables, while precipitation have a secondary role.•Data suggests a complete species turnover between the extremes of the gradients involved.

This study aimed to analyze the influence of environmental factors in determining the variation in forest structure. We obtained the data through sampling units placed regularly in a grid of 10 km × 10 km in the state of Santa Catarina, southern Brazil. The axes of Detendred Correspondence Analysis summarized the vegetation structure and we used these as response variables in ordinary least square models, and environmental variables as predictors. Moran Eigenvector Maps were used as spatial predictors, enabling the variance partitioning. The results revealed influence of climatic factors, especially thermal and rainfall in determining the vegetation structure. The physical geography (high plateaus) and positioning below the Tropic of Capricorn line are the main static elements influencing the climate and therefore the vegetation.