Atributos indicadores da dinâmica sucessional em fragmento de Mata Atlântica na região do Médio Vale do Paraíba do Sul, Pinheiral, Rio de Janeiro

Abstract

In order to choose parameters ecological attributes can be used as indicators to identify changes in environmental quality as a function of sucessional stage was selected a fragment of Atlantic Forest in the city of Pinheiral, Rio de Janeiro. Based on CONAMA 006/1994 deliberation, forest fragment areas, were classified as: initial stage succession (FIS), medium stage succession forest (FME) and advanced succession stage forest (FAS). The areas are located between latitudes 22°29’03” and 22°35’27” S and between longitudes 43°54’49” and 44°04’05” W, at an average altitude of 420 m. The ecological parameters used in this study were related to the dynamics of nutrient cycling, such as: litter input, soil fauna and organic matter. For that, at each stage of succession was demarcated one plot measuring 400 m2, within the limits of each plot samples were collected. In the Chapter I, the objectives were: estimating the annual and seasonal production of litter input, and nutrient input from litter, verify the contribution of each fraction in the total input, estimating the rate of decomposition of leaf material, and, estimating the total stock of litter and by size classes. In the Chapter II, was evaluating the effect of different successional stages of the activity, diversity and composition of soil fauna in two months of the year. The Chapter III objectives were to characterize the fertility and soil organic matter, and, to estimate carbon and nitrogen stocks. In the Chapter I, the input and stock of litter, and levels and amounts of the nutrients were statistically higher in the FEA. In the spring there was a major contribution to input, and annual precipitation and temperature were the environmental variables that most influences one. The leaf fraction and F ≥ 8 mm, respectively, accounted for the largest relative contribution of the values of the litter input and stock. The litter input was the main route of transfer of N, Ca and K to the soil, especially the N in the advanced stages and Ca in the initial and medium stages. The half-life for the FEA was 151 days, followed by FEI and FEM 217 days and 315 days respectively, observing higher losses of material throughout the study period in the FEA. In the Chapter II the FEA showed higher average activity and wealth groups, and also the most active groups of Acari, Araneae, Diptera, Formicidae, Hymenoptera. In August probably due to higher rainfall, there was the greater effect of seasonality on the attributes of the fauna. The springtails Entomobryomorpha, Poduromorpha and Symphypleona were the dominant groups. In the Chapter III, were in the FEM best levels of nutrients, mainly in the 0-10 and 10-20 cm. The attributes related to soil organic matter such as COT, COam, C-FAH and C-FAF showed higher values in the FEA. The ecological parameters evaluated in this study can be considered good indicators of environmental quality, because it responded to the state of balance and proper functioning of the ecosystem as they advanced the successional stages of forest.