Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution
Autor(a) principal: | |
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Data de Publicação: | 2015 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.5/13751 |
Resumo: | A generalized non-linear tree crown diameter model was developed with the aim of allowing the computation of tree crown diameter over a large range of tree dimensions, and allowing its inclusion in forest growth and yield models. The model was formulated to provide biological meaning to the predicted values. Due to the nested structure of the data analyzed (trees within stands), both mixed- and fixed-effect models were developed. Since tree crown diameter is not frequently measured in forest inventories, the validation of the mixed model was carried out by considering the population specific response. The results demonstrate that when the measurements required for the mixed model calibration are not available, the use of the fixed effect model results in less biased and more accurate estimates. The fixed model was applied to the data from the two last Portuguese National Forest Inventories (NFI) to analyze the change in stand crown cover and assess the stocking evolution of cork oak stands in Portugal between 1996 and 2006. Results showed an increase in the frequency of stands with crown cover lower than 20%, as well as a decrease in the frequency of stands with crown cover between 20 and 40%. Average crown cover values were significantly different in the two NFI, with a decrease from 28.0 to 26.5% over the considered period |
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Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolutionQuercus suberstand crown covertree crown diameternonlinear mixed effects modelnonlinear fixed effects modelportuguese national forest inventoryA generalized non-linear tree crown diameter model was developed with the aim of allowing the computation of tree crown diameter over a large range of tree dimensions, and allowing its inclusion in forest growth and yield models. The model was formulated to provide biological meaning to the predicted values. Due to the nested structure of the data analyzed (trees within stands), both mixed- and fixed-effect models were developed. Since tree crown diameter is not frequently measured in forest inventories, the validation of the mixed model was carried out by considering the population specific response. The results demonstrate that when the measurements required for the mixed model calibration are not available, the use of the fixed effect model results in less biased and more accurate estimates. The fixed model was applied to the data from the two last Portuguese National Forest Inventories (NFI) to analyze the change in stand crown cover and assess the stocking evolution of cork oak stands in Portugal between 1996 and 2006. Results showed an increase in the frequency of stands with crown cover lower than 20%, as well as a decrease in the frequency of stands with crown cover between 20 and 40%. Average crown cover values were significantly different in the two NFI, with a decrease from 28.0 to 26.5% over the considered periodSISEFRepositório da Universidade de LisboaPaulo, Joana AmaralFaias, SóniaVentura-Giroux, CéliaTomé, Margarida2017-06-09T12:34:42Z20152015-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.5/13751engPaulo JA, Faias SP, Ventura-Giroux C, Tomé M (2015). Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of Portuguese cork oak stands stocking evolution. iForest 9: 437-44410.3832/ifor1624-008info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-03-06T14:43:50Zoai:www.repository.utl.pt:10400.5/13751Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T16:59:41.471774Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
title |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
spellingShingle |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution Paulo, Joana Amaral Quercus suber stand crown cover tree crown diameter nonlinear mixed effects model nonlinear fixed effects model portuguese national forest inventory |
title_short |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
title_full |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
title_fullStr |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
title_full_unstemmed |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
title_sort |
Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of portuguese cork oak stands stocking evolution |
author |
Paulo, Joana Amaral |
author_facet |
Paulo, Joana Amaral Faias, Sónia Ventura-Giroux, Célia Tomé, Margarida |
author_role |
author |
author2 |
Faias, Sónia Ventura-Giroux, Célia Tomé, Margarida |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Repositório da Universidade de Lisboa |
dc.contributor.author.fl_str_mv |
Paulo, Joana Amaral Faias, Sónia Ventura-Giroux, Célia Tomé, Margarida |
dc.subject.por.fl_str_mv |
Quercus suber stand crown cover tree crown diameter nonlinear mixed effects model nonlinear fixed effects model portuguese national forest inventory |
topic |
Quercus suber stand crown cover tree crown diameter nonlinear mixed effects model nonlinear fixed effects model portuguese national forest inventory |
description |
A generalized non-linear tree crown diameter model was developed with the aim of allowing the computation of tree crown diameter over a large range of tree dimensions, and allowing its inclusion in forest growth and yield models. The model was formulated to provide biological meaning to the predicted values. Due to the nested structure of the data analyzed (trees within stands), both mixed- and fixed-effect models were developed. Since tree crown diameter is not frequently measured in forest inventories, the validation of the mixed model was carried out by considering the population specific response. The results demonstrate that when the measurements required for the mixed model calibration are not available, the use of the fixed effect model results in less biased and more accurate estimates. The fixed model was applied to the data from the two last Portuguese National Forest Inventories (NFI) to analyze the change in stand crown cover and assess the stocking evolution of cork oak stands in Portugal between 1996 and 2006. Results showed an increase in the frequency of stands with crown cover lower than 20%, as well as a decrease in the frequency of stands with crown cover between 20 and 40%. Average crown cover values were significantly different in the two NFI, with a decrease from 28.0 to 26.5% over the considered period |
publishDate |
2015 |
dc.date.none.fl_str_mv |
2015 2015-01-01T00:00:00Z 2017-06-09T12:34:42Z |
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 |
http://hdl.handle.net/10400.5/13751 |
url |
http://hdl.handle.net/10400.5/13751 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Paulo JA, Faias SP, Ventura-Giroux C, Tomé M (2015). Estimation of stand crown cover using a generalized crown diameter model: application for the analysis of Portuguese cork oak stands stocking evolution. iForest 9: 437-444 10.3832/ifor1624-008 |
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.publisher.none.fl_str_mv |
SISEF |
publisher.none.fl_str_mv |
SISEF |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
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1799131083742117888 |