Effects of environmental heterogeneity and temporal variation on ecological relationships of vegetation in a seasonally dry tropical forest in Brazil

Species distribution patterns, community structure, and dynamics are determined on a small scale by soil and habitat heterogeneity. The aim of this work is to evaluate the temporal changes in composition and structure of a tree community, revealing the ecological drivers of the observed vegetation patterns. For 16 years (2000, 2005, 2010, and 2016) we monitored the temporal variations in structure and floristic composition of a semideciduous seasonal forest through 20 x 20 m(2) (400 m(2)) plots, totaling 2.08 ha of sampled area encompassing Cambisol (0.4 ha), Oxysol (1.12 ha), and Nitosol (0.56 ha) soil classes. These tree communities were different in floristic and structural composition and showed oscillations over the years. The individual density and temporal beta diversity did not show differences among the soil classes in any of the monitoring intervals. In the other parameters, the Cambisols differed from the other soil classes, presenting the lowest species richness, greater floristic dissimilarity, and a structural pattern characterized by the dominance of Galipea jasminiflora (A.St.- Hil.) Engl. in all measurement years. From these results, we conclude that the temporal oscillations did not alter the original characteristics of the vegetation due to the species' adaptations to the environment, entailing the maintenance of the habitat characteristics and the directional development of the communities.