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| 11. |  | FIGUEIREDO, R. de O.; SOUSA, K. de A.; MARKEWITZ, D.; DAVIDSON, E. A. Alterações nas concentrações de ortofosfato em amostras de chuva, throughfall e litter leachate armazenadas em coletores instalados em área experimental na Floresta Nacional do Tapajós. In: CONGRESSO DE ECOLOGIA DO BRASIL, 6., 2003, Fortaleza, CE. Anais de trabalhos completos. Fortaleza: Universidade Federal do Ceará, 2003. p. 676-678.| Biblioteca(s): Embrapa Amazônia Oriental. |
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 | Acesso ao texto completo restrito à biblioteca da Embrapa Amazônia Oriental. Para informações adicionais entre em contato com cpatu.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Amazônia Oriental. |
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Data corrente: |
05/09/2008 |
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Data da última atualização: |
23/11/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
Internacional - A |
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Autoria: |
DAVIDSON, E. A.; ASNER, G. P.; STONE, T. A.; NEILL, C.; FIGUEIREDO, R. de O. |
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Afiliação: |
Eric A. Davidson, Woods Hole Research Center; Gregory P. Asner, Carnegie Institute; Thomas A. Stone, Woods Hole Research Center; Christopher Neill, Marine Biological Laboratory; RICARDO DE OLIVEIRA FIGUEIREDO, CPATU. |
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Título: |
Objective indicators of pasture degradation from spectral mixture analysis of landsat imagery. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
Journal of Geophysical Research: Biogeosciences, v.113, n. G1, Mar. 2008. |
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DOI: |
10.1029/2007JG000622 |
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Idioma: |
Inglês |
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Conteúdo: |
Degradation of cattle pastures is a management concern that influences future land use in Amazonia. However, ?degradation? is poorly defined and has different meanings for ranchers, ecologists, and policy makers. Here we analyze pasture degradation using objective scalars of photosynthetic vegetation (PV), nonphotosynthetic vegetation (NPV), and exposed soil (S) derived from Landsat imagery. A general, probabilistic spectral mixture model decomposed satellite spectral reflectance measurements into subpixel estimates of PV, NPV, and S covers at ranches in western and eastern Amazonia. Most pasture management units at all ranches fell along a single line of decreasing PV with increasing NPV and S, which could be considered a degradation continuum. The ranch with the highest stocking densities and most intensive management had greater NPV and S than a less intensively managed ranch. The number of liming, herbiciding, and disking treatments applied to each pasture management unit was positively correlated with NPV and negatively correlated with PV. Although these objective scalars revealed signs of degradation, intensive management kept exposed soil to <40% cover and maintained economically viable cattle production over several decades. In ranches with few management inputs, the high PV cover in young pastures declined with increasing pasture age, while NPV and S increased, even where grazing intensity was low. Both highly productive pastures and vigorous regrowth of native vegetation cause high PV values. Analysis of spectral properties holds promise for identifying areas where grazing intensity has exceeded management inputs, thus increasing coverage of senescent foliage and exposed soil. MenosDegradation of cattle pastures is a management concern that influences future land use in Amazonia. However, ?degradation? is poorly defined and has different meanings for ranchers, ecologists, and policy makers. Here we analyze pasture degradation using objective scalars of photosynthetic vegetation (PV), nonphotosynthetic vegetation (NPV), and exposed soil (S) derived from Landsat imagery. A general, probabilistic spectral mixture model decomposed satellite spectral reflectance measurements into subpixel estimates of PV, NPV, and S covers at ranches in western and eastern Amazonia. Most pasture management units at all ranches fell along a single line of decreasing PV with increasing NPV and S, which could be considered a degradation continuum. The ranch with the highest stocking densities and most intensive management had greater NPV and S than a less intensively managed ranch. The number of liming, herbiciding, and disking treatments applied to each pasture management unit was positively correlated with NPV and negatively correlated with PV. Although these objective scalars revealed signs of degradation, intensive management kept exposed soil to <40% cover and maintained economically viable cattle production over several decades. In ranches with few management inputs, the high PV cover in young pastures declined with increasing pasture age, while NPV and S increased, even where grazing intensity was low. Both highly productive pastures and vigorous regrowth of native vege... Mostrar Tudo |
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Thesagro: |
Análise do Solo; Deterioração do Solo; Pastagem; Solo; Uso da Terra. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02443naa a2200241 a 4500
001 1407127
005 2022-11-23
008 2008 bl uuuu u00u1 u #d
024 7 $a10.1029/2007JG000622$2DOI
100 1 $aDAVIDSON, E. A.
245 $aObjective indicators of pasture degradation from spectral mixture analysis of landsat imagery.$h[electronic resource]
260 $c2008
520 $aDegradation of cattle pastures is a management concern that influences future land use in Amazonia. However, ?degradation? is poorly defined and has different meanings for ranchers, ecologists, and policy makers. Here we analyze pasture degradation using objective scalars of photosynthetic vegetation (PV), nonphotosynthetic vegetation (NPV), and exposed soil (S) derived from Landsat imagery. A general, probabilistic spectral mixture model decomposed satellite spectral reflectance measurements into subpixel estimates of PV, NPV, and S covers at ranches in western and eastern Amazonia. Most pasture management units at all ranches fell along a single line of decreasing PV with increasing NPV and S, which could be considered a degradation continuum. The ranch with the highest stocking densities and most intensive management had greater NPV and S than a less intensively managed ranch. The number of liming, herbiciding, and disking treatments applied to each pasture management unit was positively correlated with NPV and negatively correlated with PV. Although these objective scalars revealed signs of degradation, intensive management kept exposed soil to <40% cover and maintained economically viable cattle production over several decades. In ranches with few management inputs, the high PV cover in young pastures declined with increasing pasture age, while NPV and S increased, even where grazing intensity was low. Both highly productive pastures and vigorous regrowth of native vegetation cause high PV values. Analysis of spectral properties holds promise for identifying areas where grazing intensity has exceeded management inputs, thus increasing coverage of senescent foliage and exposed soil.
650 $aAnálise do Solo
650 $aDeterioração do Solo
650 $aPastagem
650 $aSolo
650 $aUso da Terra
700 1 $aASNER, G. P.
700 1 $aSTONE, T. A.
700 1 $aNEILL, C.
700 1 $aFIGUEIREDO, R. de O.
773 $tJournal of Geophysical Research: Biogeosciences$gv.113, n. G1, Mar. 2008.
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