Produção e decomposição de serapilheira em um remanescente de savana estépica.

Abstract

The Caatinga is the predominant biome in northeastern Brazil. Knowledge of structural and functional components of this complex biome is still ongoing. The aim of this study was to know two of the functional componente, production and decomposition of litter, accumulation of organic lltter and the rate of decomposition in Caatinga área in the municipality of Cajazeirinhas, PB, during the period August 2013 to July 2014. Were demarcated in four transects which were performed all evaluations. For the production of litter, thirty-síx were distributed collection boxes of Im x Im, with monthly collected material deposited and separated into the following fractions: leaves, twigs, reproductive structures and miscellaneous. Every three months was collected litter accumulated in the soil, using a metal fume of 0,50 m x 0,50 m. The decomposition rate of litter was determined monthly using (litter baús) each containing 20 g of previously dried litter. The greater accumulation of litter during the study period was 3825,4 kg ha'l for the months august 2014. Litter production during the study period was 1630.5 kg ha'l, in the fraction predominated in leaves litter the ground with contributing 64,9%, then the fraction branches (21.2%) , reproductive structures (10,1%) and miscellaneous (3,8%). The highest deposition occurred at the beginning of the dry season, featuring seasonality. The highest decomposition rate for the área was for C/ofon ó/achei/ans (54,32%), followed by Z/zyphusjoaze/ro (45,86%). The highest rates of decomposition of the material packed in bags of nylon occurred at the beginning of the exposure period, resulting in the degradation of labile compounds less recalcltrant, and the process speed decreased over time, due to the permanence of the most resistant of lignified and litter.