Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories
Autor(a) principal: | |
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Data de Publicação: | 2016 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFLA |
Texto Completo: | http://repositorio.ufla.br/jspui/handle/1/14785 |
Resumo: | Forest inventories are usually compiled without taking into account the existing correlations between sampling units, which is debatable particularly where the calculations involve environmental variables. When the potential correlations between sampling units are overlooked, the accuracy of such inventories becomes distorted in terms of the confidence interval range for the variable of interest, which is volume in cubic meters. The magnitude and form of such distortion will vary according to the correlation intensity between sampling units. This study aimed to present an analysis of the addition of the correlation coefficient to the calculation of the variance of the mean in a systematic sampling procedure of a native forest population or area, as well as its impact on the accuracy of the resulting estimates, with the assumption of independence between sampling units and with the addition of a correlation between sampling units as suggested by Cochran. Results revealed that, where the correlation coefficient was added to the variance of the mean formula, it increased inventory accuracy by about 14.3%, leading to the conclusion that such an effect will occur in any forest inventory being compiled for any forest population or area of interest. |
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Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventoriesO uso do coeficiente de correlação entre parcelas visando aumento de precisão em inventários florestaisSamplingMean varianceNative forestAmostragemVariância da médiaFloresta nativaForest inventories are usually compiled without taking into account the existing correlations between sampling units, which is debatable particularly where the calculations involve environmental variables. When the potential correlations between sampling units are overlooked, the accuracy of such inventories becomes distorted in terms of the confidence interval range for the variable of interest, which is volume in cubic meters. The magnitude and form of such distortion will vary according to the correlation intensity between sampling units. This study aimed to present an analysis of the addition of the correlation coefficient to the calculation of the variance of the mean in a systematic sampling procedure of a native forest population or area, as well as its impact on the accuracy of the resulting estimates, with the assumption of independence between sampling units and with the addition of a correlation between sampling units as suggested by Cochran. Results revealed that, where the correlation coefficient was added to the variance of the mean formula, it increased inventory accuracy by about 14.3%, leading to the conclusion that such an effect will occur in any forest inventory being compiled for any forest population or area of interest. Os inventários florestais têm sido realizados sem levar em consideração a relação existente entre as unidades amostrais. Esse fato se torna altamente questionável, principalmente quando nos cálculos estão envolvidas variáveis de natureza ambiental. Ao serem desprezadas as possíveis relações entre as unidades amostrais, a precisão advinda desses inventários florestais se torna distorcida em termos de amplitude do intervalo de confiança da variável estudada, sendo esta o volume em metros cúbicos. A magnitude e a forma dessa distorção variam conforme a intensidade da correlação existente entre unidades amostrais. Dessa forma, no presente trabalho, objetivou-se apresentar uma análise da incorporação do coeficiente de correlação no cálculo da variância da média no procedimento de amostragem sistemática, em uma população ou área de floresta nativa e, seu impacto na precisão das estimativas geradas, com a suposição de independência entre as unidades amostrais e, com a adição da correlação entre as unidades amostrais, sendo esta incorporação sugerida pelo autor Cochran. Os resultados obtidos mostram que o coeficiente de correlação, quando incorporado na fórmula da variância da média, aumentou em média 14,3% a precisão dos inventários florestais avaliados neste trabalho, fato este que conclui que tal efeito ocorrerá em qualquer inventário florestal realizado para qualquer população ou área florestal a ser avaliada.Universidade Federal de Lavras (UFLA)2016-04-062017-08-01T20:17:01Z2017-08-01T20:17:01Z2017-08-01info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfSÉ, D. C. da et al. Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories. CERNE, Lavras, v. 19, n. 4, p. 575-580, out./dez. 2013.http://repositorio.ufla.br/jspui/handle/1/147852317-63420104-7760reponame:Repositório Institucional da UFLAinstname:Universidade Federal de Lavras (UFLA)instacron:UFLAengCopyright (c) 2016 CERNEAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/openAccessSé, Daniela Cunha daMello, José Márcio deScalon, João DomingosMuniz, Joel AugustoOliveira, Marcelo Silva deScolforo, José Roberto Soares2021-03-02T23:59:47Zoai:localhost:1/14785Repositório InstitucionalPUBhttp://repositorio.ufla.br/oai/requestnivaldo@ufla.br || repositorio.biblioteca@ufla.bropendoar:2021-03-02T23:59:47Repositório Institucional da UFLA - Universidade Federal de Lavras (UFLA)false |
dc.title.none.fl_str_mv |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories O uso do coeficiente de correlação entre parcelas visando aumento de precisão em inventários florestais |
title |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
spellingShingle |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories Sé, Daniela Cunha da Sampling Mean variance Native forest Amostragem Variância da média Floresta nativa |
title_short |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
title_full |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
title_fullStr |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
title_full_unstemmed |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
title_sort |
Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories |
author |
Sé, Daniela Cunha da |
author_facet |
Sé, Daniela Cunha da Mello, José Márcio de Scalon, João Domingos Muniz, Joel Augusto Oliveira, Marcelo Silva de Scolforo, José Roberto Soares |
author_role |
author |
author2 |
Mello, José Márcio de Scalon, João Domingos Muniz, Joel Augusto Oliveira, Marcelo Silva de Scolforo, José Roberto Soares |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Sé, Daniela Cunha da Mello, José Márcio de Scalon, João Domingos Muniz, Joel Augusto Oliveira, Marcelo Silva de Scolforo, José Roberto Soares |
dc.subject.por.fl_str_mv |
Sampling Mean variance Native forest Amostragem Variância da média Floresta nativa |
topic |
Sampling Mean variance Native forest Amostragem Variância da média Floresta nativa |
description |
Forest inventories are usually compiled without taking into account the existing correlations between sampling units, which is debatable particularly where the calculations involve environmental variables. When the potential correlations between sampling units are overlooked, the accuracy of such inventories becomes distorted in terms of the confidence interval range for the variable of interest, which is volume in cubic meters. The magnitude and form of such distortion will vary according to the correlation intensity between sampling units. This study aimed to present an analysis of the addition of the correlation coefficient to the calculation of the variance of the mean in a systematic sampling procedure of a native forest population or area, as well as its impact on the accuracy of the resulting estimates, with the assumption of independence between sampling units and with the addition of a correlation between sampling units as suggested by Cochran. Results revealed that, where the correlation coefficient was added to the variance of the mean formula, it increased inventory accuracy by about 14.3%, leading to the conclusion that such an effect will occur in any forest inventory being compiled for any forest population or area of interest. |
publishDate |
2016 |
dc.date.none.fl_str_mv |
2016-04-06 2017-08-01T20:17:01Z 2017-08-01T20:17:01Z 2017-08-01 |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
SÉ, D. C. da et al. Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories. CERNE, Lavras, v. 19, n. 4, p. 575-580, out./dez. 2013. http://repositorio.ufla.br/jspui/handle/1/14785 |
identifier_str_mv |
SÉ, D. C. da et al. Use of the correlation coefficient between plots in order to improvethe accuracy of forest inventories. CERNE, Lavras, v. 19, n. 4, p. 575-580, out./dez. 2013. |
url |
http://repositorio.ufla.br/jspui/handle/1/14785 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
Copyright (c) 2016 CERNE Attribution 4.0 International http://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess |
rights_invalid_str_mv |
Copyright (c) 2016 CERNE Attribution 4.0 International http://creativecommons.org/licenses/by/4.0/ |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Federal de Lavras (UFLA) |
publisher.none.fl_str_mv |
Universidade Federal de Lavras (UFLA) |
dc.source.none.fl_str_mv |
2317-6342 0104-7760 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 |
_version_ |
1784550096818405376 |