Caracterização de fragmentos de floresta estacional decidual do Parque Estadual da Lapa Grande, Montes Claros, MG

Abstract

This study aimed to characterize the floristic and structure of the component arboreal-shrub vegetation and verify their relationship with soil variables, elevation and anthropization of fragments of seasonal deciduous forest of the interior and of the surrounding State Park of Lapa Grande (SPLG). For both were allocated 25 plots of 20x20m in each area, measured the diameter and height and identified the individuals with DBH 3 cm. It was calculated the sample sufficiency, diameter structure and phytosociological parameters, and these were compared in the two areas through the test of Hotteling. For the study of floristic variation of the fragments were conducted principal component analysis (PCA) and of UPGMA clustering. Soil data, elevation and anthropization were measured for each plot and proceded to one canonical correspondence analysis or CCA to verify the correlation between these traits and species distribution. The phytosociology of the two areas was not different according to the multivariate T² (Hotelling) as explained by the recent creation of SPLG and existence of anthropized areas and preserved in the two areas. The floristic and the structure showed similar patterns, occurring only replacement of some species and exchange of some genders and families between areas due to the influence adjacent plant physiognomies like the Cerrado. The diameter structure presented pattern of "J" reverse with increase in first-class showing the large number of individuals of smaller diameter, as well as deficits in the intermediate classes and final that strengthen the adaptive strategy of this forest formation facing of a environment with soil and climatic restrictions. Cluster analysis and PCA also indicated the lack of separation between interior and surroundings. This pattern was due to the low similarity between fragments and to the floristic variation in the space marked by the influence of common characteristics to the fields as the occurrence of indicator species of the fragments: vegetation of a typical dry forest, rocky outcrops, proximity to watercourses, influence plant physiognomies and adjacent low density due to anthropization or high percentage of exposed rock. This vegetation mosaic responded in a different way to soil variables. In the combined analysis interior and surrounding there was no significance in relationships, just the surrounding established significant relationships between flora and soil, being the clay, magnesium, coarse sand and organic matter were the variables that best explained the spatial distribution of plots and species. More detailed observations of floristic and structure of each fragment and its variations, as well as their relationship with characteristics of slope, humidity and other factors that may define micro habitats should be considered in order to propose appropriate management.