Equações de volume para região sul do estado do Amazonas

Abstract

Logging under sustainable forest management has contributed to the economic development of the region. However, there is still a need for greater control over the productive quantification of the forest. Currently, the commercial volume is obtained by means of a model that is based on the multiplication of the cylinder volume by the average form factor of 0.7. Within this context, six regression models, three of which were single entry and three double entry, were tested with the objective of selecting the best model to estimate the volume of standing commercial trees in a sustainable forest management (SFM) area licensed in the municipality of Novo Aripuanã-AM, south of the state of Amazonas. A rigorous (Smalian) cubing of 361 tree-samples of 15 species and diameters ranging from 50-186 cm were used to develop volume equations. For the selection of the best model we used the statistical selection criteria, Syx (%), R² adjusted, Uncertainty (%), Akaike Information Criterion (AIC), following the ranking suggested by Bartoszeck 2000). Among the simple input models the model of Kopezky and Gehrhardt V = 0.8643 * 0.0007 * DAP² (R²aj. = 0.82) presented better results in the selection ranking, and among the models of double entry the Meyer model V = 7.3035 + (-0.1045 * DAP) + 0.0004 * DAP² + 0.0145 * (DAP * Hc) + 0.0000 * (DAP² * H) + (-0.7813 * Hc) ( R² = 0.88) was the best fit. A group of 38 sample trees were used to validate through the Chi-square statistic (X²) the volumes estimated by the volumetric models that best fit the volume observed in the cubing. The shape of the trees was defined as the mean shape factor for all species sampled (ff x ̅ = 0.68). With the use of the form factor 0.7 proposed by Heinsdijk, it overestimates the calculation of the volumetry of the Emerging Canopy Dense Ombrophylous Forest of the southern region of the municipality of Novo Aripuanã-AM, which shows the importance of adjusting local volumetric models to improve the accuracy of the estimation of the volume of standing timber and consequent release of virtual credits in the DOF System. The results show that it is possible to apply this model to determinations of the volume of standing trees in the southern region of the State of Amazonas.