BIOMASSA E NUTRIENTES EM POVOAMENTO DE Eucalyptus dunnii Maiden NO PAMPA GAúCHO1

摘要

The study aimed to quantify biomass and nutrients as well as the effects on productivity and on site, according to the intensity of harvest in stand of Eucalyptus dunnii, with four years in Alegrete-RS. The inventory was conducted for the dendrometric characterization of the stand. The trees were compartmentalized in root, stem wood, stem bark, branches and leaves. Samples were collected and analyzed for the concentration of nutrients. The total tree biomass was 121.9 Mg ha-1, with the following distribution order of components: stem wood > root >branches> stem bark > leaves. In overall terms, for aboveground biomass, there was 985 kg ha-1 macronutrients and 32,5 kg ha-1 micronutrient, distributed: N ( 24%), P ( 2%) , K (23 %) , Ca ( 34%) , Mg (13% ) and S ( 4%) and B (3%) , Cu (1%), Fe ( 7%), Mn ( 87%) and Zn (2%). Among the three harvesting scenarios evaluated Ca and K were the elements that showed the greatest risk to the maintenance of productivity.