Dinâmica estrutural em um fragmento de floresta estacional semideciduifólia em Lavras, MG, Brasil

Abstract

The present contribution aimed at describing the structural dynamics of the tree community of a forest fragment of seasonal semi-deciduous forest (Mata do Capivari) situated in Lavras, Minas Gerais State, South-eastern Brazil. The study was based on three surveys carried out during an 11-year period (1997, 2003 and 2008) in 28 20×20 m permanent plots where records were made of the species and diameter at breast height (dbh) of trees with dbh ≥ 5 cm, including survival, mortality and recruits. The hypothesis was that the patterns of dynamics found in the first interval (1997-2003) persisted in the second (2003-2008). The descriptors of dynamics were the rates of mortality and recruitment of individual trees (dynamics of demography), rates of gain and loss of tree basal area (dynamics of biomass), and respective net change rates. Between 2003 and 2008, the mortality rate, of 3.30%.yr-1, surpassed the recruitment rate, of 2.78%.yr-1. The gain rate in basal area was 2.72%.yr-1, only a little inferior to the loss rate, of 2.98%.yr-1. In general, these patterns repeated those of the first interval (1998-2003), with a persisting slow demographic decline, particularly concentrated near the river, and a nearly stable basal area. Comparatively speaking, the Mata do Capivari is one of the most stable among those studied in the region despite persistent human interference.