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Registro Completo |
Biblioteca(s): |
Embrapa Semiárido; Embrapa Soja. |
Data corrente: |
06/07/1994 |
Data da última atualização: |
01/08/2020 |
Autoria: |
WANG, S. R. |
Título: |
Effect of nitrogen and other factors on plant growth responses to vesicular-arbuscular mycorrhiza. |
Ano de publicação: |
1984 |
Fonte/Imprenta: |
London: University of London, 1984. |
Páginas: |
236 f. |
Idioma: |
Inglês |
Notas: |
Ph.D. Thesis. |
Conteúdo: |
High concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. Shading decreased mycorrhizal infection, an effect that was more pronounced with ammonium-N ((NH4)2SO4) than with nitrate-N (Ca(NO3)2.4H2O). Onion roots contained less carbohydrate in the ammonium-N than in the nitrate-N treatment and the differences were greater in shaded plants. These results showed a direct relationship between root carbohydrate levels and early VA mycorrhizal infection in young onion seedlings, thereby supporting the "Carbohydrate theory" of Bjorkman for ectomycorrhiza. MenosHigh concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. S... Mostrar Tudo |
Palavras-Chave: |
Crescimento de planta; Efeito; Fungus; Growth; Inglaterra; Mycorrhiza; Phosphatos; Plant; VA; Vesicular-arbuscular. |
Thesagro: |
Carboidrato; Crescimento; Fosfato; Fungo; Micorriza; Nitrogênio; Planta; Simbiose. |
Thesaurus Nal: |
England; nitrogen; plant growth; symbiosis. |
Categoria do assunto: |
-- X Pesquisa, Tecnologia e Engenharia |
Marc: |
LEADER 02953nam a2200397 a 4500 001 1444507 005 2020-08-01 008 1984 bl uuuu m 00u1 u #d 100 1 $aWANG, S. R. 245 $aEffect of nitrogen and other factors on plant growth responses to vesicular-arbuscular mycorrhiza. 260 $aLondon: University of London$c1984 300 $a236 f. 500 $aPh.D. Thesis. 520 $aHigh concentrations of phosphate in plants have been found to decrease vesicular-arbuscular (VA) mycorrhizal infection and its effect on plant growth, However, little is known about the effect of nitrogen on the VA mycorrhizal symbiosis, and this was examined in the present study. Mycorrhizal infection in onion was inhibited by nitrogen not only when N was added to soil, but also when were dipped into a solution containing N. Per cent N in the root tissues was increased in both cases. By contrast, infection and nitrogen concentrations in white clover were little a affected by added nitrogen. The level of nitrogen in the plant rather than in the soil was believed to be the major factor affecting infection. Similar results were obtained with other legume-non-legume combinations. In other tests with legumes, nodulation was stimulated by the VA fungus. The forms of nitrogen are important to mycorrhizal plants and their effects are influenced by soil phosphate levels. In experiments with onions growing in a soil in which they both N and P deficient, plants only responded to added nitrogen when phosphate was also applied. Non-mycorrhizal plants given phosphate grew well with both Ca(NO3)2.4H2O and NH4NO3. Mycorrhizal plants grew bigger with nitrogen added as Ca(NO3)2.4H2O than as NH4NO3; when a small amount of P was applied, mycorrhizal plants grew equally well with either form of N. It was inferred that mycorrhiza is inhibited more by ammonium-nitrogen than by nitrate-nitrogen. Shading decreased mycorrhizal infection, an effect that was more pronounced with ammonium-N ((NH4)2SO4) than with nitrate-N (Ca(NO3)2.4H2O). Onion roots contained less carbohydrate in the ammonium-N than in the nitrate-N treatment and the differences were greater in shaded plants. These results showed a direct relationship between root carbohydrate levels and early VA mycorrhizal infection in young onion seedlings, thereby supporting the "Carbohydrate theory" of Bjorkman for ectomycorrhiza. 650 $aEngland 650 $anitrogen 650 $aplant growth 650 $asymbiosis 650 $aCarboidrato 650 $aCrescimento 650 $aFosfato 650 $aFungo 650 $aMicorriza 650 $aNitrogênio 650 $aPlanta 650 $aSimbiose 653 $aCrescimento de planta 653 $aEfeito 653 $aFungus 653 $aGrowth 653 $aInglaterra 653 $aMycorrhiza 653 $aPhosphatos 653 $aPlant 653 $aVA 653 $aVesicular-arbuscular
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Embrapa Soja (CNPSO) |
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Registro Completo
Biblioteca(s): |
Embrapa Amazônia Oriental. |
Data corrente: |
05/10/2015 |
Data da última atualização: |
30/05/2022 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Circulação/Nível: |
B - 3 |
Autoria: |
SIST, P.; BLANC, L.; MAZZEI, L.; BARALOTO, C.; AUSSENAC, R. |
Afiliação: |
Plinio Sist, CIRAD; Lilian Blanc, CIRAD; LUCAS JOSE MAZZEI DE FREITAS, CPATU; Christopher Baraloto, INRA; Raphaël Aussenac, Université Antilles-Guyane. |
Título: |
Current knowledge on overall post-logging biomass dynamics in Northern Amazonian forests. |
Ano de publicação: |
2012 |
Fonte/Imprenta: |
Bois et Forêts des Tropiques, n. 314, p. 41-49, 2012. |
Idioma: |
Inglês |
Conteúdo: |
This article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Pará, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the aboveground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha ). In Cikel the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to improve the growth of residual trees, it is compulsory to apply adequate silvicultural treatments such as selective thinning or removal of vines. While the two forests are geographically close enough, their regenerative abilities differ and because of the significant difference in size of the trees, the forest could tolerate more intensive harvesting in French Guiana MenosThis article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Pará, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the aboveground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha ). In Cikel the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to... Mostrar Tudo |
Thesagro: |
Biomassa; Silvicultura. |
Thesaurus NAL: |
Amazonia. |
Categoria do assunto: |
K Ciência Florestal e Produtos de Origem Vegetal |
Marc: |
LEADER 02445naa a2200205 a 4500 001 2025754 005 2022-05-30 008 2012 bl uuuu u00u1 u #d 100 1 $aSIST, P. 245 $aCurrent knowledge on overall post-logging biomass dynamics in Northern Amazonian forests.$h[electronic resource] 260 $c2012 520 $aThis article presents the effects of logging on the dynamics of above-ground biomass from the results of the post-logging study within two forests: Cikel in Eastern Pará, Brazil and Paracou in French Guiana. The main objective is to compare the impact of commercial logging on the regeneration of the aboveground biomass in these forests whose characteristics differ in terms of structure and growth. In both sites, the intensity of exploitation is a key factor in determining the loss of biomass and the time required for its regeneration. In Paracou, the regeneration of biomass lost during conventional logging of 10 trees per hectare takes 45 years and more than 100 years when operating with higher intensity (21 trees/ha ). In Cikel the forest biomass regenerates after 49 years harvesting 6 trees/ha and that takes 87 years after removal of 8 trees/ha. This regeneration needs similar time on both sites but with lower logging intensity at Cikel, in which felled trees are larger with a greater biomass than those of Paracou. This post-logging study has established a direct correlation of the dynamics of the biomass with the initial structure of the forest, as well as with the parameters of forest dynamics: mortality, growth and recruitment. The accumulation of biomass by the tree growth of the two remaining stands is a key parameter for the net carbon storage, while the contribution of recruitment in Paracou becomes significant only after 10 years after felling. Therefore in view to improve the growth of residual trees, it is compulsory to apply adequate silvicultural treatments such as selective thinning or removal of vines. While the two forests are geographically close enough, their regenerative abilities differ and because of the significant difference in size of the trees, the forest could tolerate more intensive harvesting in French Guiana 650 $aAmazonia 650 $aBiomassa 650 $aSilvicultura 700 1 $aBLANC, L. 700 1 $aMAZZEI, L. 700 1 $aBARALOTO, C. 700 1 $aAUSSENAC, R. 773 $tBois et Forêts des Tropiques$gn. 314, p. 41-49, 2012.
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