Dinâmica da comunidade arbórea em um fragmento de cerrado Sensu Stricto em Minas Gerais, Brasil

Abstract

Studies of the dynamics in vegetal communities are essential to understand the cerrado ecology's behavior, especially considering its wide geographical distribution and heterogeneity. This kind of study helps to comprehend the mechanisms that maintain the community, generating subsidies for its conservation. This study aimed to analyze the tree community's dynamics over five years in a cerrado sensu stricto swath of 87ha. It wass protected from fire for about 30 years and is located in the municipality of Olhos-d'Água, North of Minas Gerais State, Brazil. The assumed hypothesis was that the period of protection from fire was sufficient for the community to stabilize its dynamics and thus, to compose a mature structure. The data obtained refer to 24 permanent plots of 1.000 m2 (total of 2.4 ha), where all trees with diameter at breast high 1.30 above the soil (DBH) ≥ 5 cm were marked, measured and sampled in the years 2005 and 2010. The changes in the phytosociological structure were analyzed and the mortality and recruitment rates were estimated basing on the density, gain and loss in basal area, stability and turnover times, and the periodic annual increment of the community and populations. This cerrado area presented a dynamic balance, with little variation in floristic composition and phytosociological and the structuring of the woody component had increased relatively. The populations' growth that is sensitive to fire suggests an ecological succession influenced by the absence of fire.