TAPER FUNCTION AND TIMBER ASSORTMENTS FOR Araucaria angustifolia

Abstract

Fun\ue7\uf5es de afilamento permitem determinar classes de dimens\ue3o e volumes das \ue1rvores com aplica\ue7\ue3o direta no planejamento das atividades t\ue9cnicas e econ\uf4micas da floresta. Com esse prop\uf3sito, os objetivos do presente estudo foram descrever o afilamento do fuste de Araucaria angustifolia (Bertol.) Kuntze na por\ue7\ue3o compreendida entre o n\uedvel do solo e a inser\ue7\ue3o da copa de \ue1rvores de remanescente florestal nativo, bem como ajustar modelo de regress\ue3o para a rela\ue7\ue3o altura/DAP, para o di\ue2metro na inser\ue7\ue3o da copa sobre o DAP e demonstrar a aplica\ue7\ue3o das fun\ue7\uf5es com a confec\ue7\ue3o de uma tabela de sortimentos de madeira. Oitenta e cinco \ue1rvores tiveram medidas seus di\ue2metros e alturas relativas pelo m\ue9todo de cubagem rigorosa de Hohenadl, assim como o di\ue2metro na inser\ue7\ue3o da copa com o Criterion RD 1000. Os modelos de afilamento ajustados por regress\ue3o foram o polin\uf4mio do 5\uba grau, Kozak (1988), Lee et al. (2003) e Sharma e Zhang (2004). O coeficiente de determina\ue7\ue3o ajustado (R\ub2aj), o erro padr\ue3o da estimativa em porcentagem (Syx%) e a an\ue1lise gr\ue1fica entre valores estimados e observados foram as estat\uedsticas usadas para avaliar o ajuste e a precis\ue3o dos modelos. O modelo da rela\ue7\ue3o altura/DAP e do di\ue2metro no ponto de inser\ue7\ue3o da copa alcan\ue7aram boas estat\uedsticas de ajuste e precis\ue3o, permitindo sua aplica\ue7\ue3o em invent\ue1rios florestais e no planejamento da produ\ue7\ue3o florestal. A flexibilidade e a efici\ueancia do modelo de Kozak (1988) em predizer di\ue2metros e volumes at\ue9 o ponto de inser\ue7\ue3o da copa favorecem o uso e obten\ue7\ue3o de sortimentos de madeira de arauc\ue1ria.Taper functions allow determining size classes and volumes of trees with direct application in the planning of technical and economic forest activities. For this purpose, the aim of this study was to describe the taper of the trunk of Araucaria angustifolia (Bertol.) Kuntze in the portion between the ground level and the insertion of the crown of individuals in remnant of native forest. Also tried to fit the regression model to represent relations height/DBH, diameter at the insertion of the crown in function DBH and the development of assortment timber table. Eighty-five trees were measured their diameters and heights relatives using Hohenadl cubed method and the diameter of the insertion crown with Criterion RD 1000 instrument. The taper models were adjusted by regression analysis using polynomial of the 5th degree, Kozak (1988), Lee et al. (2003) and Sharma and Zhang (2004). The adjusted coefficient of determination (R\ub2aj), the standard error of estimate in percentage (Syx%) and graphical analysis between estimated values in function of observed were used statistics to evaluate the quality of fit and models precision. The model height/DBH and diameter at the insertion point of the crown evidence good fit statistical and precision, allowing its application in activities intended at planning and forest inventories. The flexibility and efficiency of Kozak (1988) model in predicting diameters and volumes until the crown insertion point favors the use and obtain timber assortments of araucaria