Plant-induced changes of soil carbon and nitrogen dynamics in lowland Amazonia, Brazil.

摘要

The principal objective that guided this study was to determine if plantations consisting of tree species with contrasting phenologies, resource requirements, and biochemical characteristics had significantly changed carbon (C) and nitrogen (N) dynamics in a lowland tropical ecosystem when planted on an initially uniform soil. The replicated, monospecific plots consisted of Pinus caribaea var. hondurensis, Euxylophora paraensis Huber, Carapa guianensis Aubl., and a Leguminosae combination (Dalbergia nigra Allemao ex Benth., Parkia multijuga Bent., Dinizia excelsa Ducke). The experimental plots were established in the Curua-Una Forest Reserve in the east-central Amazon Basin, and replicated plots in adjacent, undisturbed native forest were used as a control. Soils under the experimental units were determined to be homogeneous based on mineralogical, textural, and chemical analyses of surface and subsurface soils. During the year examined (September 1994 to October 1995), the plantations and the native forest control produced widely varying quantities of aboveground litterfall (8 to 10.3 t ha