Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia
Comparative measurements of radiation flux components and turbulent fluxes of energy and CO2 are made at two sites in South West Amazonia: one in a tropical forest reserve and one in a pasture. The data were collected from February 1999 to September 2002, as part of the Large Scale Biosphere-Atmosph...
| Autor principal: | Von Randow, Celso |
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| Outros Autores: | Manzi, Antônio Ocimar, Kruijt, Bart J., Oliveira, Paula Afonso de, Zanchi, Fabrício Berton, Silva, Roberta Lane de Oliveira, Hodnett, Martin G., Gash, John H.C., Elbers, Jan A., Waterloo, M. J., Cardoso, Fernando Luiz, Kabat, Pavel |
| Grau: | Artigo |
| Idioma: | English |
| Publicado em: |
Theoretical and Applied Climatology
2020
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| Acesso em linha: |
https://repositorio.inpa.gov.br/handle/1/18954 |
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oai:repositorio:1-18954 |
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oai:repositorio:1-18954 Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia Von Randow, Celso Manzi, Antônio Ocimar Kruijt, Bart J. Oliveira, Paula Afonso de Zanchi, Fabrício Berton Silva, Roberta Lane de Oliveira Hodnett, Martin G. Gash, John H.C. Elbers, Jan A. Waterloo, M. J. Cardoso, Fernando Luiz Kabat, Pavel Carbon Flux Comparative Study Energy Flux Grassland Seasonal Variation Tropical Forest Amazonia South America Comparative measurements of radiation flux components and turbulent fluxes of energy and CO2 are made at two sites in South West Amazonia: one in a tropical forest reserve and one in a pasture. The data were collected from February 1999 to September 2002, as part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). During the dry seasons, although precipitation and specific humidity are greatly reduced, the soil moisture storage profiles down to 3.4 m indicate that the forest vegetation continues to withdraw water from deep layers in the soil. For this reason, seasonal changes observed in the energy partition and CO2 fluxes in the forest are small, compared to the large reductions in evaporation and photosynthesis observed in the pasture. For the radiation balance, the reflected short wave radiation increases by about 55% when changing from forest to pasture. Combined with an increase of 4.7% in long wave radiation loss, this causes an average reduction of 13.3% in net radiation in the pasture, compared to the forest. In the wet season, the evaporative fraction (λE/Rn) at the pasture is 17% lower than at the forest. This difference increases to 24% during the dry season. Daytime CO2 fluxes are 20-28% lower (in absolute values) in the pasture compared to the forest. The nighttime respiration in the pasture is also reduced compared to the forest, with averages 44% and 57% lower in the wet and dry seasons, respectively. As the reduction in the nocturnal respiration is larger than the reduction in the daytime uptake, the combined effect is a 19-67% higher daily uptake of CO2 in the pasture, compared to the forest. This high uptake of CO2 in the pasture site is not surprising, since the growth of the vegetation is constantly renewed, as the cattle remove the biomass. © Springer-Verlag 2004. 2020-06-15T22:04:09Z 2020-06-15T22:04:09Z 2004 Artigo https://repositorio.inpa.gov.br/handle/1/18954 10.1007/s00704-004-0041-z en Volume 78, Número 1-3, Pags. 5-26 Restrito Theoretical and Applied Climatology |
| institution |
Instituto Nacional de Pesquisas da Amazônia - Repositório Institucional |
| collection |
INPA-RI |
| language |
English |
| topic |
Carbon Flux Comparative Study Energy Flux Grassland Seasonal Variation Tropical Forest Amazonia South America |
| spellingShingle |
Carbon Flux Comparative Study Energy Flux Grassland Seasonal Variation Tropical Forest Amazonia South America Von Randow, Celso Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| topic_facet |
Carbon Flux Comparative Study Energy Flux Grassland Seasonal Variation Tropical Forest Amazonia South America |
| description |
Comparative measurements of radiation flux components and turbulent fluxes of energy and CO2 are made at two sites in South West Amazonia: one in a tropical forest reserve and one in a pasture. The data were collected from February 1999 to September 2002, as part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). During the dry seasons, although precipitation and specific humidity are greatly reduced, the soil moisture storage profiles down to 3.4 m indicate that the forest vegetation continues to withdraw water from deep layers in the soil. For this reason, seasonal changes observed in the energy partition and CO2 fluxes in the forest are small, compared to the large reductions in evaporation and photosynthesis observed in the pasture. For the radiation balance, the reflected short wave radiation increases by about 55% when changing from forest to pasture. Combined with an increase of 4.7% in long wave radiation loss, this causes an average reduction of 13.3% in net radiation in the pasture, compared to the forest. In the wet season, the evaporative fraction (λE/Rn) at the pasture is 17% lower than at the forest. This difference increases to 24% during the dry season. Daytime CO2 fluxes are 20-28% lower (in absolute values) in the pasture compared to the forest. The nighttime respiration in the pasture is also reduced compared to the forest, with averages 44% and 57% lower in the wet and dry seasons, respectively. As the reduction in the nocturnal respiration is larger than the reduction in the daytime uptake, the combined effect is a 19-67% higher daily uptake of CO2 in the pasture, compared to the forest. This high uptake of CO2 in the pasture site is not surprising, since the growth of the vegetation is constantly renewed, as the cattle remove the biomass. © Springer-Verlag 2004. |
| format |
Artigo |
| author |
Von Randow, Celso |
| author2 |
Manzi, Antônio Ocimar Kruijt, Bart J. Oliveira, Paula Afonso de Zanchi, Fabrício Berton Silva, Roberta Lane de Oliveira Hodnett, Martin G. Gash, John H.C. Elbers, Jan A. Waterloo, M. J. Cardoso, Fernando Luiz Kabat, Pavel |
| author2Str |
Manzi, Antônio Ocimar Kruijt, Bart J. Oliveira, Paula Afonso de Zanchi, Fabrício Berton Silva, Roberta Lane de Oliveira Hodnett, Martin G. Gash, John H.C. Elbers, Jan A. Waterloo, M. J. Cardoso, Fernando Luiz Kabat, Pavel |
| title |
Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| title_short |
Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| title_full |
Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| title_fullStr |
Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| title_full_unstemmed |
Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia |
| title_sort |
comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in south west amazonia |
| publisher |
Theoretical and Applied Climatology |
| publishDate |
2020 |
| url |
https://repositorio.inpa.gov.br/handle/1/18954 |
| _version_ |
1787145095077691392 |
| score |
11.755432 |