Nfluência da composição de espécies florestais no microclima de sub-bosque de plantios jovens de restauração

Abstract

Studies evaluating the pioneer tree species capacity to provide favorable conditions to natural regeneration in forest restoration plantings are still scarce. Thus, the aim of this study was to evaluate whether pioneer tree species affect differentially the microclimate conditions of the understory in forest restoration plantations. Two forest restoration sites, with three and five years old, were selected in a semi-deciduous forest in Itu city, São Paulo State, Brazil. In each site, five individuals of five pioneer species were studied. In the three years old site, Luehea grandiflora, Schinus terebinthifolius, Solanum erianthum, Croton urucurana and Cecropia pachystachya were studied, and in the five years old site, plants of the species L. grandiflora, S. terebinthifolius, Apeiba tibourbou, C. urucurana and S. erianthum were selected. Each species was considered as a sampling unit. Tree species height and canopy cover, air relative humidity and soil and air temperature were analyzed. In the three years old restoration site no effect of species in microclimatic conditions was found. However, in the five years old restoration site, microclimatic conditions were significantly different among species. Therefore, the importance of a careful choice of pioneer tree species as ecosystem engineers which modify environmental conditions and facilitate natural regeneration in forest restoration projects was emphasized.