Estrutura da comunidade arbórea e heterogeneidade ambiental em uma floresta ciliar montana na APA da Mantiqueira, em Aiuruoca, MG, Brasil

Abstract

The objective of this study was to evaluate the composition and structure of the tree community in a montane riparian forest and analyze the correlations of the community with the physical and chemical soil attributes, topographical and altitudinal environmental variables. The fragments studied are in the Environmental Protection Area of the Mantiqueira Mountains, in the area of influence of the future Aiuruoca Small Hydro Power Plant, located in the Upper Rio Grande, Aiuruoca municipality, Minas Gerais. The sample was 30 plots of 10x40m (1.2ha), which included all woody plants ≥ 5 cm diameter, measured at 1.30cm soil. Altogether 2362 individuals were sampled, belonging to 241 species of 124 genera and 53 families. There were differences in composition and structure between the slope and riparian habitats. Of the 20 most important species in VI, only Anadenanthera colubrina, Machaerium villosum, Tapirira obtusa and Machaerium brasiliense were common to both environments. The diversity Shannon index (H ') were high, with values of 4.66 and 4.54 nats/individual, and evenness (J') were 0.88 and 0.89. The phytosociological parameters and floristic composition were similar to other studies in the region common to the riparian forests of the Upper Rio Grande. Floristic elements were recorded as rare sensu Oliveira-Filho, Terminalia januariensis, Ilex breviscuspis and Ilex sapotifolia, featuring advanced stages of conservation. Although found great environmental heterogeneity in the attributes of soil and topography, it is believed that the main actors in structuring the plant community studied were the disturbances of natural origin due to flooding regime.