Quantification and modeling of macronutrients in bracatinga stands

Abstract

Quantification of nutrients in forest ecosystems is fundamental for the verification of the maintenance of continuous flow between what is deposited in the soil and what is re-assimilated by the plants. Using basal area as a practical tool in the measurement of forest stands makes modeling easy at stand level for nutrient quantification. Thus, the present work had as objective to quantify and fit the weight of macronutrients per hectare in different compartments of above ground biomass. The data used in this research came from 304 temporary plots with different ages in Mimosa scabrella Bentham. (bracatinga) stands located in the metropolitan region of Curitiba. Twenty three mathematical models were evaluated. Only one model was selected and validateds and it was appropriate for the estimation of nutrients quantities per hectare found in above ground of bracatinga biomass. In decrease order, the estimated values of macronutrients found in the aerial parts of bracatinga stands followed the sequence of N > Ca > K > Mg > P. After the exploitation of fire wood, were left as remnants in the area 25% of Ca, 32% of Mg, 37% of N, 45% of P and 18% of K.