Volumetric equations for Eucaliptus sp in the cerrado tocantinense

Abstract

The objective of this work was to select volumetric equations for GG-100, VM-58 and seminal Eucalyptus clones, in Aliança, south of the state of Tocantins. Data were collected in a 7-year-old Eucalyptus plantation with a spacing of 2.5m x 4.0m (1,000 trees/ha). The selection of trees for cubage was carried out from a systematic forest inventory and stratified by clone and seminal for later determination of the diameter distribution. Cubing was performed using the Smaliam method on 48 trees with DBH ≥ 12 cm until the entire diameter distribution was covered. 10 traditional mathematical models were adjusted for each species of eucalyptus. The best fitted models for each species were determined through the values ​​of R2aj and CV (%) together with the graphical analysis of residues. The best models were: lnv=-11.6833+1.4379*lnd+1.9246*lnh (Schumacher Hall) for VM-58 with the R2aj =0.88 and CV% =5.00, the lnv= model 6.6775+1.7840*lnd (Husch) for GG-100 with R2aj= 0.77 and CV%= 34.89 and lnv=-9.6711+2.8759*lnd+0.0762*lnh (Schumacher Hall) for Seminal, with R2aj= 0.91 and CV%= 10.12. Through the tukey test, no significant difference was observed in the DAP and volume variables between the clones.