Acúmulo, deposição e decomposição de serrapilheira sob a dinâmica vegetacional da caatinga, em unidade de conservação.

Abstract

Nutrient cycling is essential for maintaining the productivity of forest ecosystems, especially on soils of low fertility and strongly weathered. Despite the studies of accumulation and deposition of litter in the Caatinga vegetation, there is still much to our understanding of the dynamics of this biome. This study aimed to evaluate the accumulation, deposition and decomposition of litter in order to obtain information about the dynamics of plant species in a Private Reserve of Natural Heritage in Caatinga biome (Reserva Particular do Patrimônio Natural) in the state of Paraíba, to provide future studies regarding nutrient cycling, to facilitate future studies regarding nutrient cycling, and evaluate the role of rainfall seasonality in these events. To obtain the litterfall production, we used 20 collectors of 1.0m x 1.0 m, with nylon fabric background. The collection was done monthly, the litter was separated into leaves, twigs, reproductive material and miscellaneous and were dried in an oven and then weighed. To evaluate the quantification of the stock of accumulated litter, we used a metal frame with dimensions of 0.5m x 0.5m, thrown randomly being and being collected monthly, then taken to the laboratory oven to dry and to be weighed. The deposition fraction of leaf litter in the year 2011 was estimated at 2079.61 kg ha-1, representing 77.23% of the total estimate for the experimental period. We conclude that the litterfall followed the order: leaves > bark + branches > reproductive material > miscellany. The litter accumulated on the forest floor in the study area can be decomposed almost completely in about two years.