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Equacoes de volume para uma floresta secundaria no planalto do Tapajos Belterra, PA.

by Silva, J.N.M; Carvalho, M.S.P. de.
Other Title: Volume equations for a secondary forest in the Tapaj©đs plateau - Belterra, Para.Subject(s): DIAMETRO | VOLUMEN | ANALISIS ESTADISTICO | BOSQUE SECUNDARIO | VOCHYSIA MAXIMA | BRASIL | DIAMETER | VOLUME | STATISTICAL ANALYSIS | SECONDARY FORESTS | BRAZIL | DIAMETRE | VOLUME | ANALYSE STATISTIQUE | FORET SECONDAIRE | BRESIL In: Boletim de Pesquisa Florestal - EMBRAPA. Centro Nacional de Pesquisa de Florestas (Brasil) (no.8/9) p. 1-15Summary: Single and two parameter volume equations were developed for a secondary forest located in the Tapajos plateau-Belterra, Para. Sixty sample-trees of several species were measured to produce general equation and sixty Vochysia maxima trees were measured to obtain equations for this particular species. The sample trees were measured according to an uniforme distribution. Eleven models found in the literature and two equations obtained by stepwise regression were compared. The tables of the relative residuals [(YSummary: - y)/£MS residual] showed eleven outliers in the dataset for the general equation and twelve in the dataset for Vochysia maxima equation. By omitting the outliers the precision of the equations was increased by 60 per cent. Although the use of a uniform distribution has improved the precision of the equations it did not completely removed the bias (parameter) in the estimates of the volume in extreme diameter classes. The two parameter equations obtained by stepwise regression showed better results than the models found in the literature.
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Single and two parameter volume equations were developed for a secondary forest located in the Tapajos plateau-Belterra, Para. Sixty sample-trees of several species were measured to produce general equation and sixty Vochysia maxima trees were measured to obtain equations for this particular species. The sample trees were measured according to an uniforme distribution. Eleven models found in the literature and two equations obtained by stepwise regression were compared. The tables of the relative residuals [(Y

- y)/£MS residual] showed eleven outliers in the dataset for the general equation and twelve in the dataset for Vochysia maxima equation. By omitting the outliers the precision of the equations was increased by 60 per cent. Although the use of a uniform distribution has improved the precision of the equations it did not completely removed the bias (parameter) in the estimates of the volume in extreme diameter classes. The two parameter equations obtained by stepwise regression showed better results than the models found in the literature.

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