Estrutura e diversidade da comunidade arbórea do Parque Natural Municipal da Lajinha (Juiz de Fora, MG, Brasil)

Abstract

The aim of this study is to provide information about the conservation status, structure and composition of the Parque Natural Municipal da Lajinha, Juiz de Fora, Minas Gerais State, Brazil. Randomly placed and georeferenced 25 permanent plots of 20 x 20 m, totaling 1393 individuals living arboreal and 145 dead in sampled (CAP ≥ 15,7 cm), belonging to 155 species, 100 genera and 51 families. Nectandra nitidula, Eugenia hiemalis, Bathysa australis, Virola bicuhyba, Alchornea triplinervea are the five species with higher IV as Fabaceae (23), Myrtaceae (14), Lauraceae (11), Euphorbiaceae (8), Sapindaceae (7), Meliaceae (5), Monimiaceae (5) and Rubiaceae (5) are families with the highest species richness. The Shannon diversity index (H’) was one of the highest recorded for the region's forests (H’ = 4,36 nats.ind-1), containing including endangered species (Ocotea odorifera, Virola bicuhyba, Dicksonia sellowiana), according to Red Book of Brazilian flora. Half community and most dead fall within the first class proposal diameter (7,5 cm), which reflects the high degree of competition. The community diametric distribution followed the model "J-reverse" standard for tropical forest communities. The high evenness index of evenness (J’ = 0.866) shows low ecological dominance and high floristic heterogeneity of the community, floristic confirmed by cluster analysis (Morisita-Horn coefficient) is less than 0,5, and DCA, which showed values greater than 0,3 (Axis 1 = 0,49 and Axis 2 = 0,33). The result of floristic similarity analysis using qualitative coefficient of Jaccard highlights the importance of species of low density in the sample. These results expose the complexity of the operating dynamics of biotic processes present in a secondary forest community. Further resampling studies may analyze functional aspects and attributes of these species and their effective role in community. The presence of rare species for the state of Minas Gerais, the availability of resources for the regional fauna and high diversity index shows the biological potential of the Natural Park of Lajinha and reinforces the need to adapt the same to become a Unit Conservation.