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Registro Completo |
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Biblioteca(s): |
Embrapa Florestas. |
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Data corrente: |
13/01/2009 |
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Data da última atualização: |
08/07/2010 |
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Autoria: |
BELINI, U. L.; TOMAZELLO FILHO, M.; CHAGAS, M. P.; OLIVEIRA, J. T. da S. |
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Título: |
Alterações na estrutura anatômica da madeira de cavacos de Eucalyptus grandis em três condições de desfibramento para a confecção de painéis MDF. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
Revista Árvore, Viçosa, v. 32, n. 3, p. 513-522, maio/jun. 2008. |
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Idioma: |
Português |
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Conteúdo: |
A utilização da madeira de eucalipto na confecção de painéis MDF é recente, tornando-se necessário entender as modificações em sua estrutura anatômica durante as etapas do processo industrial, notadamente no desfibramento dos cavacos. Com esse objetivo, neste estudo foram aplicadas três condições diferenciadas de desfibramento dos cavacos, alterando-se (i) o tempo de aquecimento, (ii) as pressões de digestão e de desfibramento e (iii) a energia específica de desfibramento, sendo avaliadas as características anatômicas dos componentes celulares da madeira. O aumento da intensidade de refino dos cavacos de madeira reduziu o comprimento médio das fibras e aumentou o porcentual de fibras quebradas, corroborando as imagens de microscopia eletrônica de varredura, além da diminuição do número dos vasos e de células de parênquima. Essa condição de desfibramento mais intensa promoveu, também, um característico escurecimento da coloração da polpa composta pelos elementos celulares da madeira. A aplicação de variáveis de desfibramento mais brandas aumentou a presença de feixes de fibras e do número de vasos e de parênquima, resultando em uma polpa de coloração mais clara. As alterações das características morfológicas dos componentes celulares da madeira dos cavacos de eucalipto, após o tratamento de desfibramento, relacionaram-se com as etapas do processo operacional e com a qualidade tecnológica dos painéis de fibras MDF. |
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Palavras-Chave: |
Anatomia da madeira; Cavacos; Desfibramento; Painel MDF. |
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Thesagro: |
Eucalyptus Grandis. |
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Categoria do assunto: |
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Marc: |
LEADER 02183naa a2200217 a 4500
001 1315299
005 2010-07-08
008 2008 bl uuuu u00u1 u #d
100 1 $aBELINI, U. L.
245 $aAlterações na estrutura anatômica da madeira de cavacos de Eucalyptus grandis em três condições de desfibramento para a confecção de painéis MDF.
260 $c2008
520 $aA utilização da madeira de eucalipto na confecção de painéis MDF é recente, tornando-se necessário entender as modificações em sua estrutura anatômica durante as etapas do processo industrial, notadamente no desfibramento dos cavacos. Com esse objetivo, neste estudo foram aplicadas três condições diferenciadas de desfibramento dos cavacos, alterando-se (i) o tempo de aquecimento, (ii) as pressões de digestão e de desfibramento e (iii) a energia específica de desfibramento, sendo avaliadas as características anatômicas dos componentes celulares da madeira. O aumento da intensidade de refino dos cavacos de madeira reduziu o comprimento médio das fibras e aumentou o porcentual de fibras quebradas, corroborando as imagens de microscopia eletrônica de varredura, além da diminuição do número dos vasos e de células de parênquima. Essa condição de desfibramento mais intensa promoveu, também, um característico escurecimento da coloração da polpa composta pelos elementos celulares da madeira. A aplicação de variáveis de desfibramento mais brandas aumentou a presença de feixes de fibras e do número de vasos e de parênquima, resultando em uma polpa de coloração mais clara. As alterações das características morfológicas dos componentes celulares da madeira dos cavacos de eucalipto, após o tratamento de desfibramento, relacionaram-se com as etapas do processo operacional e com a qualidade tecnológica dos painéis de fibras MDF.
650 $aEucalyptus Grandis
653 $aAnatomia da madeira
653 $aCavacos
653 $aDesfibramento
653 $aPainel MDF
700 1 $aTOMAZELLO FILHO, M.
700 1 $aCHAGAS, M. P.
700 1 $aOLIVEIRA, J. T. da S.
773 $tRevista Árvore, Viçosa$gv. 32, n. 3, p. 513-522, maio/jun. 2008.
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Registro original: |
Embrapa Florestas (CNPF) |
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Registro Completo
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Biblioteca(s): |
Embrapa Florestas; Embrapa Recursos Genéticos e Biotecnologia. |
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Data corrente: |
27/09/2021 |
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Data da última atualização: |
16/12/2021 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
RESENDE, R. T.; SILVA, P. I. T.; SILVA JUNIOR, O. B. da; FREITAS, M. L. M.; SEBBENN, A. M.; SOUSA, V. A. de; AGUIAR, A. V. de; GRATTAPAGLIA, D. |
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Afiliação: |
RAFAEL T. RESENDE, Universidade federal de Goiás; PEDRO ITALO T. SILVA, Universidade de Brasília; ORZENIL BONFIM DA SILVA JUNIOR, Cenargen; MIGUEL L. MENEZES FREITAS, Instituto Florestal de São Paulo; ALEXANDRE M. SEBBENN, Instituto Florestal de São Paulo; VALDERES APARECIDA DE SOUSA, CNPF; ANANDA VIRGINIA DE AGUIAR, CNPF; DARIO GRATTAPAGLIA, Cenargen. |
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Título: |
Age trends in genetic parameters for growth performance across country-wide provenances of the iconic conifer tree Araucaria angustifolia show strong prospects for systematic breeding and early selection. |
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Ano de publicação: |
2021 |
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Fonte/Imprenta: |
Forest Ecology and Management, v. 501, 119671, Dec. 2021. 13 p. |
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DOI: |
https://doi.org/10.1016/j.foreco.2021.119671 |
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Idioma: |
Inglês |
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Conteúdo: |
Understanding the growth patterns of long-lived conifer tree species is important to devise breeding and early
selection strategies, predict future biomass productivity and assess adaptive tree fitness for long term conservation efforts. We investigated the genetic variation for growth traits of Araucaria angustifolia, the grandiose
renowned ?Parana ´ pine? tree, in a trial involving 122 families across 15 provenances covering the entire natural
range of the species in Brazil. Measurements at ages 7, 24, 32, 33 and 35 were used to adjust continuous growth
curves based on nonlinear mixed-effect models for all 2158 trees, providing annual estimates for unmeasured
ages in the 7-to-35-year interval. Estimated values closely matched observed ones and a reduction of the coefficient of residual variation was observed in the estimated data, possibly due to removal of random error in the
observed measurements, making the estimated curves more reliable to predict growth patterns. Genetic variation
for growth within provenances was greater than between, with a trend of increasing heritabilities over time for
most provenances. Substantial genetic variation found both within and between families could drive efficient
early selection at both levels. All provenances included individual trees and families with good potential to be
selected for shorter rotations. Growth curves show that trees invest first in height and later in diameter growth.
Considerable variation was observed across provenances for the optimal age and optimal tree volume at which
annual growth increment peaks, a tipping point that could be used as a predictor of the optimal rotation age and
expected tree volume. The data clearly indicate potential for early selection for growth at age 7?10 with an 85%
prediction accuracy of growth at age 35. Additionally, growth data indicate potential of shortening harvest age
from 30?35 to 15?20 years by selecting the best individuals and families. These results underscore the potential
of expanding investments in breeding and plantation forestry of A. angustifolia, which in parallel could contribute
to enhancing conservation efforts of this iconic subtropical conifer. MenosUnderstanding the growth patterns of long-lived conifer tree species is important to devise breeding and early
selection strategies, predict future biomass productivity and assess adaptive tree fitness for long term conservation efforts. We investigated the genetic variation for growth traits of Araucaria angustifolia, the grandiose
renowned ?Parana ´ pine? tree, in a trial involving 122 families across 15 provenances covering the entire natural
range of the species in Brazil. Measurements at ages 7, 24, 32, 33 and 35 were used to adjust continuous growth
curves based on nonlinear mixed-effect models for all 2158 trees, providing annual estimates for unmeasured
ages in the 7-to-35-year interval. Estimated values closely matched observed ones and a reduction of the coefficient of residual variation was observed in the estimated data, possibly due to removal of random error in the
observed measurements, making the estimated curves more reliable to predict growth patterns. Genetic variation
for growth within provenances was greater than between, with a trend of increasing heritabilities over time for
most provenances. Substantial genetic variation found both within and between families could drive efficient
early selection at both levels. All provenances included individual trees and families with good potential to be
selected for shorter rotations. Growth curves show that trees invest first in height and later in diameter growth.
Considerable variation was observed ... Mostrar Tudo |
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Palavras-Chave: |
Conifer breeding; Genetic parameters; Individual tree modeling; Mixed models; Random regression. |
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Thesagro: |
Araucária Angustifólia; Pinheiro do Paraná. |
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Thesaurus NAL: |
Early selection. |
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Categoria do assunto: |
G Melhoramento Genético |
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URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/226395/1/1-s2.0-S0378112721007611-main.pdf
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Marc: |
LEADER 03310naa a2200313 a 4500
001 2134780
005 2021-12-16
008 2021 bl uuuu u00u1 u #d
024 7 $ahttps://doi.org/10.1016/j.foreco.2021.119671$2DOI
100 1 $aRESENDE, R. T.
245 $aAge trends in genetic parameters for growth performance across country-wide provenances of the iconic conifer tree Araucaria angustifolia show strong prospects for systematic breeding and early selection.$h[electronic resource]
260 $c2021
520 $aUnderstanding the growth patterns of long-lived conifer tree species is important to devise breeding and early selection strategies, predict future biomass productivity and assess adaptive tree fitness for long term conservation efforts. We investigated the genetic variation for growth traits of Araucaria angustifolia, the grandiose renowned ?Parana ´ pine? tree, in a trial involving 122 families across 15 provenances covering the entire natural range of the species in Brazil. Measurements at ages 7, 24, 32, 33 and 35 were used to adjust continuous growth curves based on nonlinear mixed-effect models for all 2158 trees, providing annual estimates for unmeasured ages in the 7-to-35-year interval. Estimated values closely matched observed ones and a reduction of the coefficient of residual variation was observed in the estimated data, possibly due to removal of random error in the observed measurements, making the estimated curves more reliable to predict growth patterns. Genetic variation for growth within provenances was greater than between, with a trend of increasing heritabilities over time for most provenances. Substantial genetic variation found both within and between families could drive efficient early selection at both levels. All provenances included individual trees and families with good potential to be selected for shorter rotations. Growth curves show that trees invest first in height and later in diameter growth. Considerable variation was observed across provenances for the optimal age and optimal tree volume at which annual growth increment peaks, a tipping point that could be used as a predictor of the optimal rotation age and expected tree volume. The data clearly indicate potential for early selection for growth at age 7?10 with an 85% prediction accuracy of growth at age 35. Additionally, growth data indicate potential of shortening harvest age from 30?35 to 15?20 years by selecting the best individuals and families. These results underscore the potential of expanding investments in breeding and plantation forestry of A. angustifolia, which in parallel could contribute to enhancing conservation efforts of this iconic subtropical conifer.
650 $aEarly selection
650 $aAraucária Angustifólia
650 $aPinheiro do Paraná
653 $aConifer breeding
653 $aGenetic parameters
653 $aIndividual tree modeling
653 $aMixed models
653 $aRandom regression
700 1 $aSILVA, P. I. T.
700 1 $aSILVA JUNIOR, O. B. da
700 1 $aFREITAS, M. L. M.
700 1 $aSEBBENN, A. M.
700 1 $aSOUSA, V. A. de
700 1 $aAGUIAR, A. V. de
700 1 $aGRATTAPAGLIA, D.
773 $tForest Ecology and Management$gv. 501, 119671, Dec. 2021. 13 p.
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Embrapa Recursos Genéticos e Biotecnologia (CENARGEN) |
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