Efeitos da limitação de nutrientes sobre parâmetros de produtividade de uma floresta madura na Amazônia Central.

Abstract

The nutritional status of the soil influences the interactions between the different forest compartments, their stocks and productivity. The addition of nutrients in old soils tends to increase leaf nutrient vitamins and the assimilation of carbon by vegetation. In contrast, higher nutrients of nutrients in the leaves can increase herbivory, loss in leaf loss and decrease in carbon assimilation through photosynthesis. Therefore, this work aims to understand the role of nutritional limitation on photosynthesis and productivity above ground, considering the effects of herbivory. This study was carried out in the area of ​​the large-scale fertilization experiment in the Amazon (AFEX). Eight treatments were distributed in four blocks (32 plots), with the addition of nitrogen (N), phosphorus (P) and cations (K, Ca, Mg). In these plots, the photosynthesis of canopy trees, the concentration of leaf nutrients, leaf herbivory, litter production and wood productivity were measured between the years 2017 and 2019. There was an increase in the concentration of Ca, Mg and P in the leaves , after adding nutrient qualities. In the areas where addition of P added, the aggregated leaves had a higher concentration of P and photosynthetic rates were higher, as well as the production of litter. No relevant differences were observed in the production of wood and herbivory in the fertilized areas. These results obtained that some nutrients, mainly P, limit the productivity of this ecosystem