Influência da forma de ajuste e do comprimento das seções no desempenho de funções de afilamento

• Autor(a) principal: Môra, Rômulo
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/5770
• topic: Taper functions; Sections length; Precision; Funções de afilamento; Comprimento das seções; Precisão; Recursos Florestais e Engenharia Florestal; Levantamentos florestais; Florestas - Uso múltiplo; Florestas - Medição; Eucalipto; Pesquisa florestal; 630

This work had as objective to verify the accuracy and precision of estimates of diameter, height and volume variables, considering the estimates of the parameter obtained in the adjustment of data set by the original model and the expressions in diameter and height for different taper models and sections length. To conduct the study, 70 stems of Eucalyptus urophylla x Eucalyptus grandis hybrid were cubed in a spacing of 3 x 2 m, in a stand of 3,48 hectares with 8 years-old, in sections of 0,5 m until they reach a minimum diameter of 4 cm for the study of taper functions. To check the influence of the sections length, all stems were measured in ten different sections lengths corresponding to 0,5 m, 1,0 m, 1,5 m, 2,0 m, 2,5 m, 3,0 m, 3,5 m, 4,0 m, 4,5 m and 5 m, starting from the section of 0,0 m to a minimum diameter of 4 cm and separated into two groups, one considering the influence of the base and the other not. The models used in the comparison of the estimates are the ones proposed by Baldwin, Demaerschalk, Kozak and Ormerod. In the study of the sections length influence, it was used the model proposed by Demaerschalk in the different analyzed sections lengths. The precision and accuracy of the estimates were verified by graphic analysis of the waste, the determination coefficient ( ), estimated standard error (Syx(%)), bias (V), average of the differences (MD) and standard deviation of the differences (DPD). Based on these statistics, a classification was made to determine the model that would provide better variables estimates by different types of adjustment and sections length, estimating more accurate results for the analyzed variables. Diameter, height and volume variables estimates were obtained more accurately for the Demaerschalk model, considering the parameters estimates obtained from the expressions of the diameter and height variables in relation to estimates based on parameters estimates of the original model. In the study of the influence of the sections length, it can be seen that as the number of sections measures in the stem decreases, it becomes possible to verify the presence of tendency of the variables estimates for both groups. Comparing the results of the group, with and without influence of the basis, it is noted that the estimates with influence are better, which was observed mainly to the volume variable