The objective of the present study was to evaluate the efficiency of volumetric
adjustments for Lecythis lurida in the Tapajos National Forest. The data came from
100% inventory and and rigorous species counting in UPA 8. 301 trees were selected
from Lecythis lurida with 50 cm ≥ DAP <150 cm, where 8 volumetric models were
fitted. For the choice of the best equation, we analyzed the significance of the
coefficients by the t test, adjusted coefficient of determination, standard error of the
estimate, and factor of inflation of the variance to verify situations of multicollinearity,
graphical analysis and histograms of residues. For the validation of the best equation,
the actual and estimated volume were compared by the chi-square test at 95%
probability. The combined Spurr variable models, Husch, Schumacher Hall and Spurr -
both logarithmized presented significance of all parameters by the t test. Regarding the
precision parameters, the Spurr combined variable models, Schumacher Hall and Spurr
logarithmized presented the best values. After the removal of outliers is clear the
improvement in the parameters of precision of the models. In relation to the graphical
distribution of the residues, the Schumacher and Spurr logarithmized models presented
similar results, but when analyzing the other criteria of selection of the best model,
Spurr combined variable was considered the most adequate to estimate the volumetry of
the species in the area for its simplicity of application. The selected equation generated
estimates that did not differ statistically with real volume according to the chi-square
test.
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