A leguminosa arbórea Acacia mangium Willd é espécie de rápido crescimento, sobre a qual são raros os trabalhos publicados no Brasil. No presente estudo foram abatidas 125 árvores com sete anos de idade, em Botucatu-SP. As árvores amostradas apresentavam troncos múltiplos com valores médios de 14,9 m de altura total, 8,50 cm de dap, 10,82% de porcentagem de casca e 0,4704 de fator de forma. Foram testados sete modelos de equação de regressão para estimativas dos volumes totais de madeira com casca (vtcc) e sem casca (vtsc) e dos volumes comerciais com e sem casca (vccc e vcsc) ao diâmetro limite de 4 cm com casca, em função das variáveis dap com casca (d) e altura total (h). O modelo selecionado foi o de Meyer modificado.
There are a few papers published about the fast growing tree species Acacia mangium Willd in Brazil. In this study 125 stems were sampled in 7-years-old trees, in Botucatu, State of Sao Paulo. The mean values of the sampled stems were: total height = 14.9 m; dbh = 8.50 cm (trees with multiple stems); form factor = 0.4704 and bark percentage = 10.82 %. Seven regression models were compared in order to estimate the tree total-stem wood volume outside bark (tvob), as a function of tree dbh outside bark (d) and total height (h). The same models were also compared to estimate total stem-volume inside bark (tvib), and merchantable-stem volumes outside and inside bark (mvob and mvib) to a 4.0 cm diameter top outside bark. Meyer’s modified model was selected, resulting in the following four tree volume equations: tvob = - 83781 + 38100d – 3373.921449d 2 - 1182.119898dh + 180.492446d 2 h; tvib = - 75146 + 34932d - 3140.342475d 2 - 1101.933853dh + 168.089354d 2 h; mvob = - 84854 + 38875d – 3430.779373d 2 - 1200.264989dh + 182.693837d 2 h e mvib = - 78752 + 35592d – 3187.349100d 2 - 1116.657350dh + 169.872490d 2 h in which volumes are expressed in dm 3 , diameter in cm and height in m.
