Modelos para estimar o volume de madeira da reserva extrativista Auatí- Paraná, na região do Alto Solimões, Fonte Boa (AM)

Abstract

Sustainable Forest Management relies on precise and consistent qualitative and quantitative wood volume estimation for regions, sites and forest species. Therefore volume equations are indispensable for the forest manager to plan and evaluate the stand’s potential stock and yield. This study was carried out in the area of the Reserva Extrativista Auatí-Paraná, located on the Fonte Boa municipality, Upper Solimões region, Amazonas State. 18 volumetric models (six single- and twelve double-entry equations) were tested based on cubing 206 newly fallen trees. With regards to general models, among the double entry equations, Schumacher-Hall original model attained the best fit, with a R 2aj = 0,95; S yx = 5,18% and good residues distribution, superior to the single-entry models. Husch’s logarithmic model was the better fit among the single-entry models, attaining a R 2 aj =0,95, S yx =11,5% and a good residue distribution. Fitting the equations for the trees in the 10 < DAP < 50 cm diametric class resulted in more precision than the through general equations. The logarithmic double-entry model, ln V = a + b lnDAP 2 HC, with Spurr’s combined variable fitted best (R 2 aj = 0,97 e S yx = 4,18%). Among the single entry equations in this diametric class the model ln V = a + b ln DAP achieved a good performance (R 2 aj = 0,92 e S yx = 6,46%). Fitting equations to the diametric class DAP > 50 cm however, resulted in no improvements from the general models. Also three species had equations fitted to them: tauari (Cariniana sp . ), castanha-sucupira (Curupira tefeensis) and anoerá (Beilschmiedia brasiliensis). The first two species had good non-linear exponential fit. Husch’s single-entry equation is recommended for local use in the forest management at the Resex and the is recommended for regional use in other sites of similar forests. The use of newly fallen trees as a data record to generate models is viable and consistent. Cubing the fallen trees in good condition is easy to obtain and execute in tropical forests.