Compartmentalization and efficiency biological of nitrogen utilization in dry tropical forest

Abstract

Studies of nutrient efficiency and compartmentalization of nutrients in dry forests can contribute to the understanding of the nutrition of these forests because significant nutrient depositions come from leaf and branch fractions and are mostly derived from leguminous species, emphasizing the importance of nitrogen in cycling of these environments. This work aimed to determine the compartmentalization and efficiency biological of nitrogen utilization of the forest species with the highest importance value in a fragment of Caatinga hiperxerófila in Pernambuco. In the species was estimated the leaf biomass, using allometric equations. Leaves and stem parts were sampled for determination of nitrogen content. The biological utilization efficiency was calculated for each species. The biomass of the stem was 10.12 kg plant-1 and of the leaf was 0.99 kg plant-1. Higher N contents were observed in the leaves and stem of Poincianella bracteosa, associated to the high biomass of the species. The most efficient species to use nitrogen were Myracrodruon urundeuva and Bauhinia cheilantha, which could be indicated for areas with low levels of organic matter.