Seasonality influence the nutrient content of litter fall in secondary forest in the Amazonian

摘要

Secondary forest vegetation in the Bragantina area, Northeast of Pará State, is characterized by the abandonment of anthropized forests, locally known as capoeiras, in different successional stages. The current study aims to evaluate the nutrient concentrations in order to identify the treatment that have caused greater nutrient deficiency due to full and partial litter spacing well as to assess the capoeira with best nutrient cycling performance. The study area is located in 10-and-40-year-old secondary forests in Bragan?a County, Benjamin Constant community, Northeastern Pará State. Litter samples were collected during the dry and rainy seasons. The chemical analysis of the macro and micronutrients were further performed. The decreasing order of the herein observed nutrient concentration was N> Ca> Mg> In> K> P. By taking under consideration the 40-year-old capoeira and the treatments applied to the 10-year-old one (no thinning (NT), partial thinning (PT), and total thinning (TT)), it is possible to state that the highest concentrations in all analyzed elements showed the same descending order in micronutrient concentrations: Fe> Mn > Zn> Cu. The different-aged capoeiras within the Bragantina area showed that not all nutrients were influenced by seasonality, despite the applied thinning type, the vegetation age and the forest species.