This study aimed to evaluate the structure and diversity of the tree community in a secondary semidecidous forest at UFJF Botanical Garden (Juiz de Fora, Minas Gerais, Brazil). The trees (dbh≥ 5 cm) were sampled at 25 random plots of 20 m × 20 m. A total of 2535 individuals were sampled, 385 standing dead and 2150 life, belonging to 105 species and 39 families. As a reflection of strong ecological dominance, the index value of species diversity (Shannon H'= 3.30 nats.ind-1) was low compared to secondary forests of the region. The standing dead trees represent 15.2% of individuals, a high proportion compared to secondary forests. Detrended correspondence analysis (DCA) resulted in short gradients, showing a low internal species heterogeneity. There was a strong predominance of species of early succession stages (pioneer and early secondary). The results show that, although the forest has undergone over 70 years of natural regeneration, the tree community presents a slow succession process, with low diversity and characteristics of an immature forest. In contrast, the area has endangered species and some families typical of mature forest (Lauraceae and Myrtaceae). In other words, the fragment is important for the preservation of regional biodiversity.
phytosociology; permanent plots; ecological succession; conservation; Atlantic Forest
