Desenvolvimento de modelos biométricos para predição de volume de plantios de Dendrocalamus asper (Schult f.) Backer ex Heyne

Abstract

Dendrocalumus asper is an exotic bamboo species with great productive potential. But when the subject is to quantify the productivity of bamboo, there is a lack in the literature about models for estimating the apparent volume and actual volume of bamboo stalks. In view of the above, the objective of the present work was to obtain predictive models for the apparent volume and the actual volume for the species Dendrocalamus asper. For this, rigorous cubing procedures were performed on 180 stems of the species, extracted from a fertilization experiment at the Universidade Tecnológica Federal do Paraná, Dois Vizinhos campus. The experiment is composed of an area of 1.6 ha, with a planting spacing of 10 meters between rows and 7 meters between clumps, comprising 12 plots with 4 clumps in the row and 5 clumps between rows, totaling 240 clumps in the experiment. Thirty volumetric models were tested for the apparent volume and for the actual volume, where they were evaluated according to the following adjustment qualities: adjusted determination coefficient adjusted R², Furnival index in percentage (IF %) and graphic analysis of residuals, selecting as results the 10 best volumetric models for each volume. For both the apparent volume and the actual volume, all the selected volumetric models obtained a good fit and a reasonable predictive capacity. For the two volumes analyzed, the model proposed by Schumacher-Hall stood out, presenting for the apparent volume an adjusted R² of 0.9509 and IF (%) of 8.70 % and for the actual volume an adjusted R² of 0.7913 and IF (%) of 15.00 %. It is concluded with the study, that the 10 selected models for both the apparent volume and the actual volume, present good adjustments and a reasonable predictive capacity for the species Dendrocalamus asper, being able to produce accurate and satisfactory estimates. But among the adjusted volumetric models, the model proposed by Schumacher-Hall, was the one that stood out best through the selection criteria of adjustment, for the apparent volume and the actual volume, being able to produce accurate and satisfactory estimates for the volumes analyzed.