Height-diameter models in forestry with inclusion of covariates

Detalhes bibliográficos
Autor(a) principal: Guimarães, Mayara A. M.
Data de Publicação: 2009
Outros Autores: Calegário, Natalino, Carvalho, Luis Marcelo Tavares de, Truguilho, Paulo F.
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Institucional da UFLA
Texto Completo: http://repositorio.ufla.br/jspui/handle/1/872
Resumo: The main difficulty in selecting height-diameter relationships is the large number of variables involved. Techniques for decomposition of model parameters with inclusion of covariates relating to individual trees and to the stand collectively can improve model precision. This study aimed to evaluate quality improvement in the fit of height-diameter models by inclusion of covariates. The data in this study was obtained from commercial Eucalyptus sp. plantations in southern Bahia state. Firstly two reduced models were fitted, one linear and another nonlinear, considering the same trend of height variation as a function of diameter, for all genetic materials being studied. Between the two, the logistic model presented the best performance for the relevant database. After fitting parameters for the selected model, the complete formulation was fit with inclusion of variables relating to individual trees, which improved model precision. A reduction of 17% was observed in the residual standard error value when comparing reduced model and complete model, with inclusion of covariates.
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spelling Height-diameter models in forestry with inclusion of covariatesModelos hipsométricos florestais com a inclusão de covariantesEucalyptusHeight-diameter relationshipModelingEucalyptusRelação hipsométricaModelagemThe main difficulty in selecting height-diameter relationships is the large number of variables involved. Techniques for decomposition of model parameters with inclusion of covariates relating to individual trees and to the stand collectively can improve model precision. This study aimed to evaluate quality improvement in the fit of height-diameter models by inclusion of covariates. The data in this study was obtained from commercial Eucalyptus sp. plantations in southern Bahia state. Firstly two reduced models were fitted, one linear and another nonlinear, considering the same trend of height variation as a function of diameter, for all genetic materials being studied. Between the two, the logistic model presented the best performance for the relevant database. After fitting parameters for the selected model, the complete formulation was fit with inclusion of variables relating to individual trees, which improved model precision. A reduction of 17% was observed in the residual standard error value when comparing reduced model and complete model, with inclusion of covariates.A principal dificuldade na modelagem da relação hipsométrica é o grande número de variáveis que a influenciam. Diante disso, técnicas de decomposição dos parâmetros do modelo, com a inclusão de covariantes relacionadas com árvores individuais e com o povoamento, podem melhorar a precisão do mesmo. Este estudo foi realizado com o objetivo de avaliar a melhoria da qualidade do ajuste de modelos hipsométricos pela inclusão de covariantes. Os dados do presente estudo são provenientes de plantios comerciais de Eucalyptus sp. situados na região sul do estado da Bahia. Inicialmente, foram ajustados dois modelos reduzidos, um linear e um não linear, considerando a mesma tendência de variação da altura em função do diâmetro, para todos os materiais genéticos estudados. Entre os dois modelos, o logístico foi o que apresentou melhor performance para a base de dados em questão. Após o ajuste dos parâmetros do modelo selecionado, a formulação completa foi ajustada com a inclusão das variáveis relativas à árvore individual, melhorando-se, com isso, a precisão do modelo. Houve uma redução de 17% no valor do erro padrão residual quando comparados o modelo reduzido e o modelo completo, com a inclusão das covariantes.2013-08-06T21:29:28Z2013-08-06T21:29:28Z2009info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfGUIMARÃES, M. A. M. et al. Height-diameter models in forestry with inclusion of covariates. Cerne, Lavras, MG, v. 15, n. 3, p. 313-321, jul./set. 2009.http://repositorio.ufla.br/jspui/handle/1/872CERNEreponame:Repositório Institucional da UFLAinstname:Universidade Federal de Lavras (UFLA)instacron:UFLAGuimarães, Mayara A. M.Calegário, NatalinoCarvalho, Luis Marcelo Tavares deTruguilho, Paulo F.info:eu-repo/semantics/openAccesseng2013-09-04T17:35:25Zoai:localhost:1/872Repositório InstitucionalPUBhttp://repositorio.ufla.br/oai/requestnivaldo@ufla.br || repositorio.biblioteca@ufla.bropendoar:2013-09-04T17:35:25Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA)false
dc.title.none.fl_str_mv Height-diameter models in forestry with inclusion of covariates
Modelos hipsométricos florestais com a inclusão de covariantes
title Height-diameter models in forestry with inclusion of covariates
spellingShingle Height-diameter models in forestry with inclusion of covariates
Guimarães, Mayara A. M.
Eucalyptus
Height-diameter relationship
Modeling
Eucalyptus
Relação hipsométrica
Modelagem
title_short Height-diameter models in forestry with inclusion of covariates
title_full Height-diameter models in forestry with inclusion of covariates
title_fullStr Height-diameter models in forestry with inclusion of covariates
title_full_unstemmed Height-diameter models in forestry with inclusion of covariates
title_sort Height-diameter models in forestry with inclusion of covariates
author Guimarães, Mayara A. M.
author_facet Guimarães, Mayara A. M.
Calegário, Natalino
Carvalho, Luis Marcelo Tavares de
Truguilho, Paulo F.
author_role author
author2 Calegário, Natalino
Carvalho, Luis Marcelo Tavares de
Truguilho, Paulo F.
author2_role author
author
author
dc.contributor.author.fl_str_mv Guimarães, Mayara A. M.
Calegário, Natalino
Carvalho, Luis Marcelo Tavares de
Truguilho, Paulo F.
dc.subject.por.fl_str_mv Eucalyptus
Height-diameter relationship
Modeling
Eucalyptus
Relação hipsométrica
Modelagem
topic Eucalyptus
Height-diameter relationship
Modeling
Eucalyptus
Relação hipsométrica
Modelagem
description The main difficulty in selecting height-diameter relationships is the large number of variables involved. Techniques for decomposition of model parameters with inclusion of covariates relating to individual trees and to the stand collectively can improve model precision. This study aimed to evaluate quality improvement in the fit of height-diameter models by inclusion of covariates. The data in this study was obtained from commercial Eucalyptus sp. plantations in southern Bahia state. Firstly two reduced models were fitted, one linear and another nonlinear, considering the same trend of height variation as a function of diameter, for all genetic materials being studied. Between the two, the logistic model presented the best performance for the relevant database. After fitting parameters for the selected model, the complete formulation was fit with inclusion of variables relating to individual trees, which improved model precision. A reduction of 17% was observed in the residual standard error value when comparing reduced model and complete model, with inclusion of covariates.
publishDate 2009
dc.date.none.fl_str_mv 2009
2013-08-06T21:29:28Z
2013-08-06T21:29:28Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/article
format article
status_str publishedVersion
dc.identifier.uri.fl_str_mv GUIMARÃES, M. A. M. et al. Height-diameter models in forestry with inclusion of covariates. Cerne, Lavras, MG, v. 15, n. 3, p. 313-321, jul./set. 2009.
http://repositorio.ufla.br/jspui/handle/1/872
identifier_str_mv GUIMARÃES, M. A. M. et al. Height-diameter models in forestry with inclusion of covariates. Cerne, Lavras, MG, v. 15, n. 3, p. 313-321, jul./set. 2009.
url http://repositorio.ufla.br/jspui/handle/1/872
dc.language.iso.fl_str_mv eng
language eng
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.source.none.fl_str_mv CERNE
reponame:Repositório Institucional da UFLA
instname:Universidade Federal de Lavras (UFLA)
instacron:UFLA
instname_str Universidade Federal de Lavras (UFLA)
instacron_str UFLA
institution UFLA
reponame_str Repositório Institucional da UFLA
collection Repositório Institucional da UFLA
repository.name.fl_str_mv Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA)
repository.mail.fl_str_mv nivaldo@ufla.br || repositorio.biblioteca@ufla.br
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