Species tolerance degree to soil conditions shaping plant communities

Understanding vegetation-environment relationships enables perceiving past and present patterns and to predict responses to future scenarios, thereby being useful for conservation and understanding evolutionary processes. In this context, the objective of our study was to test the hypothesis that niche processes at local scales (< 1 km2) are significantly expressive in plant communities structuring. For this, we selected the more representative and widely distributed sampled species, and then modelled their representativeness as a function of edaphic variables. The data were obtained in four fragments of seasonal semi-deciduous forests located in a transition area between the Atlantic and Cerrado biogeographic domains, Brazil. A total of 92 plots with 63 of 400 m2 and 29 of 300 m2 were randomly distributed in the fragments. Individuals that reached the inclusion criterion (circumference at breast height ≥ 15.7 cm) in each plot were measured and identified and soil samples were also collected. Then, we calculated the relative abundance and relative basal area in each plot. All species showed significant relationships with the soil variables, as their representativeness showed to be correlated (positively and/or negatively) with at least one restrictive fertility or texture condition. Therefore, the results confirm the tested hypothesis, evidencing the niche processing role in community structuring through the species tolerance degree to soil conditions.