BIOMASSA MICROBIANA EM ÁREAS EM PROCESSO DE RESTAURAÇÃO NA RESERVA BIOLÓGICA DE POÇO DAS ANTAS, RJ

Abstract

Soil microbial biomass (SMB) is considered a significant nutrient pool in soils, that may be associated to changes in the vegetation cover. In order to estimated the SMB C and N contents, six treatments were installed in mature forests (F), 8-year-old mixed plantations of indigenous tree species (P), and abandoned pastures (G), at both the flooding (V) and the sloping (M) areas of the Poço das Antas Biological Reserve, an Atlantic Rain Forest remnant of ca. 5,200ha. Soil samples were collected at the layers 0-2.5cm, and were incubated to also measure soil respiration rates. There was no significant difference among the treatments for SMB-C content and for the soil respiration rate, but the plantation on the flooding area showed a higher value for SMB-N than that on the sloping area plantation. Higher values of metabolic quotient (qCO2) and of Cmic:Nmic ratio suggest the plantation on the sloping area has a lower stability than the plantation on the flooding area.