Dinâmica da comunidade arbórea de um fragmento de floresta estacional semidecidual localizada na reserva legal da Fazenda Irara, Uberlândia-MG

Abstract

Tropical forests are complex and have high species diversity. The semideciduous forests were the fastest forest type and widely devastated throughout its natural range. These forests have 20% deciduousness may reach 50% in the dry season. Dynamic studies in tropical forests are key to understanding the diversity and complexity of populations in plant communities. However due to the high diversity and complexity of forest communities difficult to determine answers standards. Classify the species in ecological groups, bringing together species with similar characteristics, is a promising way to understand important issues. Thus the study aims to analyze the phytosociological patterns and the dynamics of the community and to identify and compare the representation of dynamic response groups in the area. The study was conducted at the Farm of the legal reserve Irara located in the rural municipality of Uberlândia. The first sampling of trees was held in September 2008, and all living trees with diameter at breast height ≥ 5 cm) were labeled and identified. The sample area contains 1 hectare plots were demarcated 25 20 x 20m. In 2013, the dead individuals were recorded remeasured survivors and measuring and identifying the individuals enrolled (DBH> 5 cm). The average annual rates of mortality and recruitment and the average annual rates of loss and basal area gain the community were calculated. We also evaluate, turnover rates (turnover) in number of individuals and basal area. There were four groups based on mortality and recruitment rates and four groups based in the rates and decrease. The species were also classified according to characteristics of dispersal, laminate and wood density. The forest gradient showed a decrease in the number of individuals (943-941 ind.haˉ¹) and an increase in basal area (27 to 28.41 m² / ha). In general, the rates indicate a balance between recruitment and mortality (1.82% and 1.74%, respectively). he basal area increment rate was 2.12%. The community showed a turnover rate of 1.80% of individuals and 1.67% of basal area. We use 30 species for the formation of groups, and they followed the order in relation to the number of species for mortality and recruitment G2> G3> G4> G1 and G7> G5> G8> G6 to increment and decrement. The reserve Irara Finance presented the tree layer with diversity similar to FES in the region. The values found in this study show a trend of dynamic equilibrium. And although semideciduous forests present intense dynamics, the study forest exhibited a different pattern in these five years of study, with low rates of mortality and recruitment.