Equações para estimar o peso de carbono fixado em árvores de Mimosa scabrella Bentham (Bracatinga) em povoamentos nativos

Abstract

This research aimed to generate equations for estimating fixed carbon weight of Mimosa scabrella Bentham of native stands from the Curitiba metropolitan region. The data for the development of this research came from 194 Mimosa scabrella trees distributed in stands with ages ranging from five to eighteen years located in several counties of the Curitiba metropolitan region. Every sample tree was felled down and divided in the following components: stem, thick branches (diameter 4 cm), thin branches (diameter < 4 cm), foliage, and dead branches. The green weight of each tree component was weighted in the field. Small sub samples of each tree green component were also weighted in the field and brought to the laboratory for oven drying until reaching unchanged weight. Thus, it was obtained the dry weight of the whole component of the 194 trees by extrapolation of the sample weights. Small samples of each component from 55 trees were triturated for carbon content determination. DBH, total height and stem height were the main independent variables used for modeling carbon weights equations for the components firewood, stem and total. The adjusted equations for estimating carbon weight of the leaves and of the branches presented high standard errors and low determination coefficients.