Pioneer tree responses to variation of soil attributes in a tropical semi-deciduous forest in Brazil

ABSTRACTThe occurrence of pioneer tree species inside tropical forests is usually associated with canopy openness due to disturbances. The distribution of these species under different environmental conditions, aside from light presence, can be influenced by other variables such as soil attributes, water availability, and non-arborous species presence. This work evaluates pioneer tree distribution in the Pindorama Biological Reserve, Brazil, with respect to altitude, soil attributes, and non-arborous species in 65,400-m2 plots in two toposequences of semi-deciduous forest. We evaluated the physical and chemical soil attributes altitude, basal area, height, and number of individuals of tree species with diameter at breast height (DBH) ≥5 cm in a randomly chosen quadrant in each plot. Pioneer trees were characterized by the following higher occurrence species: Acacia polyphylla, Aloysia virgata, Casearia sylvestris, and Croton floribundus. Cluster analysis suggested five similar groups among sampling plots....