O efeito da substituição da floresta com araucária por monoculturas florestais sobre a deposição de serrapilheira e a ciclagem de nutrientes

Abstract

The Araucaria Forest has a great ecologic and economic value for the southern region of Brazil. Along the last century it was intensely explored causing its conversion to grassland, agriculture or monoculture of exotic tree species. This alteration of the landscape had direct effects on physical conditions of the habitats, abundance of populations, diversity and composition of communities, and on ecosystem processes. Among the several routes of nutrient transfer on ecosystems, litter production is one of the most important ones, strongly influencing the soil-plant system. The aim of this paper was to test how the replacement of Araucaria Forest by tree monocultures affects the litter deposition process and its consequences to the nutrient cycle. In the São Francisco de Paula National Forest (RS), three one-hectare areas of each one of the following habitats were selected: Araucaria Forest (FO), Araucaria angustifolia plantation (PA), Pinus plantation (PP) and Eucalyptus plantation (PE). In each area, 12 litte