Bark volume and weight modeling of Mimosa scabrella Bentham trees in the Curitiba metropolitan region

  • Sebastião do Amaral Machado Universidade Federal do Paraná (UFPR), Brasil.
  • Luís César Rodrigues da Silva UFPR
  • Edilson Urbano UFPR
  • Marco Aurélio Figura
  • Saulo Jorge Téo
  • Lorena Stolle

Abstract

The objective of this paper was to model bark volume and weight of Mimosa scabrella Bentham trees. To achieve this objective 440 trees were cubed by the Hohenadl’s method using 10 sections. These trees had ages ranging from 6 to 17 years, and were located in several counties inside the Curitiba (Parana) metropolitan region. The stems from 194 trees were weighed in the field. Samples of bark from these trees were collected, weighed in the field (green weight) and brought to the laboratory for drying until constant weight (dry weight); thus it was calculated the relationship dry weight/green weight of the sample and extrapolation for the whole stem. For the modeling, several mathematical models from the literature for estimating dry weight of Acacia mearnsii were selected. New models based on the forward’s method were also built. Twenty different models were adjusted using the 1/d²h to weight the arithmetic models with two entries and 1/d² for the models with single entry. The best models for each case were selected basing on the adjusted coefficient of determination (R²aj), standard error of estimate in percentage (syx %) and on the residual graphic distribution. In general, the new models built with variables most correlated with the respective independent variables were the most precise. The best fitting were obtained for bark volume and green weight, with syx% ranging from 15 to 18%, and R²aj from 0.96 to 0.98. The best equation for estimating bark volume in percentage presented R²aj = 0.47 and syx% = 17%.The best models for estimating bark dry weight presented higher syx% and lower R²aj than those obtained for green weight.

Author Biography

Sebastião do Amaral Machado, Universidade Federal do Paraná (UFPR), Brasil.
Possui graduação em Engenharia Florestal pela Universidade Federal do Paraná (1965), especialização em Fotointerpretação pelo Centro Geotécnico da França Ufpr (1968), especialização em Manejo de Áreas Silvestres pelo Instituto Interamericano de Ciências Agrícolas da OEA (1969), especialização em Pós-Doutorado pela University of Georgia (1993), especialização em Treinamento Pós-Doutorado pela University Freiburg (1981), especialização em Administração e Manejo Florestal pela University of Michigan - Ann Arbor (1989), especialização em Astronomia de Campo e Geodésia pela Universidade Federal do Paraná (1970), mestrado em Dasometria, Mensuração Florestal pelo Instituto Interamericano de Ciências Agrícolas da OEA (1972) e doutorado em Biometria e Manejo Florestal pela Universidade de Washington Em Seattle Washington, U S A (1978). Atualmente é Professor Sênior da Universidade Federal do Paraná e Assessor/Consultor do Fundação Araucária de Apoio ao Conselho de Desenvolvimento Científico e Tecnológico do Paraná. Tem experiência na área de Recursos Florestais e Engenharia Florestal, com ênfase em Manejo Florestal.
Published
06/06/2007
Section
Papers