Ciclagem via serapilheira em áreas de caatinga no Núcleo de Desertificação do Seridó.

Abstract

Litter cycling in caatinga areas in the Seridó Desertification Nucleus. The litter is fundamental for the maintenance of the forest ecosystems, where the process of deposition and decomposition of this material must be studied and known, especially in regions where the soil presents nutritional deficiency. The objective of the study to evaluate the production, accumulation and decomposition of litter in Caatinga vegetation in the Paraíba State, in areas with different successional stages of regeneration. The experiment was carried out on the Cachoeira de São Porfírio Farm, in Várzea-PB, in three areas, thus characterized: initial stage, medium and advanced natural regeneration. For the collection of litter deposited were randomly distributed within each block, eight collectors of 1.0 m x 1.0 m. The collections were performed monthly during a period of 12 months. The litter accumulated on the soil surface was estimated at quarterly collections being collected nine samples in each experimental area, in which is used a hollow mold 0.5 m x 0.5 m. For the study of the decomposition by the method of the nylon bags, 42 nylon bags were distributed in each experimental area, which are laid on the soil surface at random to evaluate decomposition. The split leaves showed the best percentage of independent litter the successional stage. The months following the end of the rainy season had the highest litter production, independent of the natural regeneration stage. Litter production increases with the advancement of successional stage. The area in advanced natural regeneration had the highest litter production and accumulation. The decomposition coefficient (k) remained constant independent of the regeneration stage and the remaining material decreases exponentially with higher value in the early days. The edaphoclimatic conditions of the experimental areas provided conditions for less decomposition of litter.