Abstract

ALVEAR, Marysol et al. Biological activities and water-stable aggregates in two forest types of temperate forest of Central-Southern of Chile with antropic disturbed. Ecol. austral [online]. 2007, vol.17, n.1, pp.113-122. ISSN 1667-782X.

The increasing demand of timber-yielding and not timber-yielding products, from natural forests has increased the rate of degradation. This process makes necessary the understanding of the variables responsible for its regulation. We quantified and compared a number of biological and physical parameters in rhizospheric soil (Andisol) under two forest types (secondary and mature forest). The biological variables evaluated were the fluorescein diacetate hydrolysis (FDA), microbial biomass carbon and nitrogen, ergosterol and the activity of two enzymes involved in the carbon cycle (C) (β-glucosidase and managanese peroxidase), one involved in the nitrogen cycle (N) (urease) and one involved in the phosphorus cycle (P) (acid phosphatase). Additionally we quantified the percentage of water stable aggregates. The entire set of parameters exhibited greater values in secondary forest than those of the mature one. Our results suggest that the greater soil moisture, litter and organic matter accumulation in the secondary forest are responsible for the greater biological activity documented in this system.

Keywords : Forest ecosystems; Microbial biomass; Enzymatic activities; Water stable aggregates.

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