Indicadores de recuperação ambiental em diferentes coberturas florestais, Alegre - ES

Abstract

This study aimed to evaluate the natural regeneration, biomass and nutrients from the litter and soil chemical properties, as indicators of environmental recovery in a conservation area on the municipality of Alegre, ES. The field activities were conducted between September 2010 and March 2011, using as treatments, three different forest covers included on the Area of Ecological Interest (ARIE) Laerth Paiva Gama, being a Native Forest (MN), a reforestation of eucalyptus and acacia (REA) and Reforestation of various species (RED). Natural regeneration was evaluated by floristic and phytosociology of individuals, accumulated litter, the amount of biomass, nutrient content and accumulation in two collection periods, the first in the late dry season and the second in the late rainy season, and the soil chemical properties, analysis of fertility in two depths, 0 - 20 cm and 20 - 40 cm. In the natural regeneration of the coverage there was a low floristic diversity for REA and somewhat higher for MN and RED, high dominance of few species, equability was similar between the covers and just kind Leucaena leucocephala (Lam.) de Wit. was similar between them. In all the covers, the quantity of biomass was greater in the dry season and followed values decreasing the amount of biomass in both samples, REA > RED > MN. The levels of potassium, magnesium and boron, were also higher in the dry season, while the nitrogen, phosphorus, calcium, sulfur, copper, iron, manganese and zinc, and organic carbon content differed only between the covers. The accumulation of nutrients was higher in the dry season, also corroborating with the highest accumulation of biomass. The decreasing order of macronutrients accumulated for collection was performed in the dry season in MN and REA: N > Ca > K > Mg > S > P and RED: N > Ca > Mg > K > S > P. In the rainy season the decreasing order was N > Ca > S > Mg > K > P to MN, and N > Ca> Mg > S > K > P for REA and finally, N > Ca > Mg > K = S > P for RED. Micronutrients were the order Fe > Mn > B > Zn > Cu in the dry season. While the rainy season showed the same order for the MN and REA, and Fe > Mn > B > Zn > Cu, while for the RED was Fe > Mn > Zn > B > Cu