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![](/consulta/web/img/deny.png) | Acesso ao texto completo restrito à biblioteca da Embrapa Solos. Para informações adicionais entre em contato com cnps.biblioteca@embrapa.br. |
Registro Completo |
Biblioteca(s): |
Embrapa Solos. |
Data corrente: |
13/11/2019 |
Data da última atualização: |
11/11/2021 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Autoria: |
CHALK, P. M.; INACIO, C. de T.; CHEN, D. |
Afiliação: |
PHILLIP MICHAEL CHALK, UNIVERSITY OF MELBOURNE; CAIO DE TEVES INACIO, CNPS; DELI CHEN, UNIVERSITY OF MELBOURNE. |
Título: |
An overview of contemporary advances in the usage of 15N natural abundance (delta N-15) as a tracer of agro-ecosystem N cycle processes that impact the environment. |
Ano de publicação: |
2019 |
Fonte/Imprenta: |
Agriculture, Ecosystems & Environment, v. 283, 106570, Nov. 2019. |
DOI: |
https://doi.org/10.1016/j.agee.2019.106570 |
Idioma: |
Inglês |
Conteúdo: |
During the past 20 years there have been major advances in the application of 15N natural abundance (NA) measurements to trace the pathways and magnitudes of N fluxes in the soil-plant-atmosphere continuum. However, estimates are often not quantitative due to the unknown extent of isotopic fractionation during a particular N transformation under study, when other processes compete simultaneously for substrate. Examples are the estimation of N fertilizer use efficiency or the transfer of biologically-fixed N2 to non-fixing companion species in intercrops or crop sequences. In some cases it has been possible to identify a particular process or source leading to a change in the relative isotopic composition (delta15N signature) of a system component, by innovative selection of experimental conditions that isolate the source or process from confounding factors. Nevertheless, there are examples where significant contemporary advances have occurred in the application of NA as a quantitative tracer, such as in the estimation of the symbiotic dependence of a range of N2 fixing plants. The key is the estimation of isotopic fractionation during N2 fixation and assimilation, and new knowledge has been obtained on factors contributing to variation, and new approaches devised to obtain more accurate estimates of fractionation. A second example is the innovative application of isotopomer measurements of the potent greenhouse gas N2O that enable presumptive identification of the biological and chemical processes resulting in its production under various agricultural scenarios. MenosDuring the past 20 years there have been major advances in the application of 15N natural abundance (NA) measurements to trace the pathways and magnitudes of N fluxes in the soil-plant-atmosphere continuum. However, estimates are often not quantitative due to the unknown extent of isotopic fractionation during a particular N transformation under study, when other processes compete simultaneously for substrate. Examples are the estimation of N fertilizer use efficiency or the transfer of biologically-fixed N2 to non-fixing companion species in intercrops or crop sequences. In some cases it has been possible to identify a particular process or source leading to a change in the relative isotopic composition (delta15N signature) of a system component, by innovative selection of experimental conditions that isolate the source or process from confounding factors. Nevertheless, there are examples where significant contemporary advances have occurred in the application of NA as a quantitative tracer, such as in the estimation of the symbiotic dependence of a range of N2 fixing plants. The key is the estimation of isotopic fractionation during N2 fixation and assimilation, and new knowledge has been obtained on factors contributing to variation, and new approaches devised to obtain more accurate estimates of fractionation. A second example is the innovative application of isotopomer measurements of the potent greenhouse gas N2O that enable presumptive identification of the biological... Mostrar Tudo |
Thesagro: |
Amônia; Composto Orgânico; Fertilizante; Nitrogênio; Solo. |
Thesaurus Nal: |
Ammonia; Composts; Fertilizers; Soil. |
Categoria do assunto: |
P Recursos Naturais, Ciências Ambientais e da Terra |
Marc: |
LEADER 02420naa a2200265 a 4500 001 2114276 005 2021-11-11 008 2019 bl uuuu u00u1 u #d 024 7 $ahttps://doi.org/10.1016/j.agee.2019.106570$2DOI 100 1 $aCHALK, P. M. 245 $aAn overview of contemporary advances in the usage of 15N natural abundance (delta N-15) as a tracer of agro-ecosystem N cycle processes that impact the environment.$h[electronic resource] 260 $c2019 520 $aDuring the past 20 years there have been major advances in the application of 15N natural abundance (NA) measurements to trace the pathways and magnitudes of N fluxes in the soil-plant-atmosphere continuum. However, estimates are often not quantitative due to the unknown extent of isotopic fractionation during a particular N transformation under study, when other processes compete simultaneously for substrate. Examples are the estimation of N fertilizer use efficiency or the transfer of biologically-fixed N2 to non-fixing companion species in intercrops or crop sequences. In some cases it has been possible to identify a particular process or source leading to a change in the relative isotopic composition (delta15N signature) of a system component, by innovative selection of experimental conditions that isolate the source or process from confounding factors. Nevertheless, there are examples where significant contemporary advances have occurred in the application of NA as a quantitative tracer, such as in the estimation of the symbiotic dependence of a range of N2 fixing plants. The key is the estimation of isotopic fractionation during N2 fixation and assimilation, and new knowledge has been obtained on factors contributing to variation, and new approaches devised to obtain more accurate estimates of fractionation. A second example is the innovative application of isotopomer measurements of the potent greenhouse gas N2O that enable presumptive identification of the biological and chemical processes resulting in its production under various agricultural scenarios. 650 $aAmmonia 650 $aComposts 650 $aFertilizers 650 $aSoil 650 $aAmônia 650 $aComposto Orgânico 650 $aFertilizante 650 $aNitrogênio 650 $aSolo 700 1 $aINACIO, C. de T. 700 1 $aCHEN, D. 773 $tAgriculture, Ecosystems & Environment$gv. 283, 106570, Nov. 2019.
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Biblioteca(s): |
Embrapa Amazônia Oriental. |
Data corrente: |
15/05/2018 |
Data da última atualização: |
22/05/2018 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Circulação/Nível: |
A - 1 |
Autoria: |
ROWLAND, L.; COSTA, A. C. L. da; OLIVEIRA, A. A. R.; OLIVEIRA, R. S.; BITTENCOURT, P. L.; COSTA, P. B.; GILES, A. L.; SOSA, A. I.; COUGHLIN, I.; GODLEE, J. L.; VASCONCELOS, S. S.; S. JUNIOR, J. A.; FERREIRA, L. V.; MENCUCCINI, M.; MEIR, P. |
Afiliação: |
Lucy Rowland, University of Exeter; Antonio C. L. da Costa, UFPA; Alex A. R. Oliveira, MPEG; Rafael S. Oliveira, UNICAMP; Paulo L. Bittencourt, UNICAMP; Patricia B. Costa, UNICAMP; Andre L. Giles, UNICAMP; Azul I. Sosa, UNICAMP; Ingrid Coughlin, USP; John L. Godlee, University of Edinburgh; STEEL SILVA VASCONCELOS, CPATU; João A. S. Junior, UFPA; Leandro V. Ferreira, MPEG; Maurizio Mencuccini, CREAF / ICREA; Patrick Meir, University of Edinburgh / Australian National University. |
Título: |
Drought stress and tree size determine stem CO2 efflux in a tropical forest. |
Ano de publicação: |
2018 |
Fonte/Imprenta: |
New Phytologist, v. 218, n. 4, p. 1393-1405, June 2018. |
DOI: |
10.1111/nph.15024 |
Idioma: |
Inglês |
Conteúdo: |
CO2 efflux from stems (CO2_stem) accounts for a substantial fraction of tropical forest gross primary productivity, but the climate sensitivity of this flux remains poorly understood. We present a study of tropical forest CO2_stem from 215 trees across wet and dry seasons, at the world?s longest running tropical forest drought experiment site. We show a 27% increase in wet season CO2_stem in the droughted forest relative to a control forest. This was driven by increasing CO2_stem in trees 10?40 cm diameter. Furthermore, we show that drought increases the proportion of maintenance to growth respiration in trees > 20 cm diameter, including large increases in maintenance respiration in the largest droughted trees, > 40 cm diameter. However, we found no clear taxonomic influence on CO2_stem and were unable to accurately predict how drought sensitivity altered ecosystem scale CO2_stem, due to substantial uncertainty introduced by contrasting methods previously employed to scale CO2_stem fluxes. Our findings indicate that under future scenarios of elevated drought, increases in CO2_stem may augment carbon losses, weakening or potentially reversing the tropical forest carbon sink. However, due to substantial uncertainties in scaling CO2_stem fluxes, stand-scale future estimates of changes in stem CO2 emissions remain highly uncertain. |
Palavras-Chave: |
Estresse hídrico. |
Thesagro: |
Carbono; Floresta; Floresta Tropical. |
Categoria do assunto: |
K Ciência Florestal e Produtos de Origem Vegetal |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/176915/1/nph.15024.pdf
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Marc: |
LEADER 02323naa a2200349 a 4500 001 2091469 005 2018-05-22 008 2018 bl uuuu u00u1 u #d 024 7 $a10.1111/nph.15024$2DOI 100 1 $aROWLAND, L. 245 $aDrought stress and tree size determine stem CO2 efflux in a tropical forest.$h[electronic resource] 260 $c2018 520 $aCO2 efflux from stems (CO2_stem) accounts for a substantial fraction of tropical forest gross primary productivity, but the climate sensitivity of this flux remains poorly understood. We present a study of tropical forest CO2_stem from 215 trees across wet and dry seasons, at the world?s longest running tropical forest drought experiment site. We show a 27% increase in wet season CO2_stem in the droughted forest relative to a control forest. This was driven by increasing CO2_stem in trees 10?40 cm diameter. Furthermore, we show that drought increases the proportion of maintenance to growth respiration in trees > 20 cm diameter, including large increases in maintenance respiration in the largest droughted trees, > 40 cm diameter. However, we found no clear taxonomic influence on CO2_stem and were unable to accurately predict how drought sensitivity altered ecosystem scale CO2_stem, due to substantial uncertainty introduced by contrasting methods previously employed to scale CO2_stem fluxes. Our findings indicate that under future scenarios of elevated drought, increases in CO2_stem may augment carbon losses, weakening or potentially reversing the tropical forest carbon sink. However, due to substantial uncertainties in scaling CO2_stem fluxes, stand-scale future estimates of changes in stem CO2 emissions remain highly uncertain. 650 $aCarbono 650 $aFloresta 650 $aFloresta Tropical 653 $aEstresse hídrico 700 1 $aCOSTA, A. C. L. da 700 1 $aOLIVEIRA, A. A. R. 700 1 $aOLIVEIRA, R. S. 700 1 $aBITTENCOURT, P. L. 700 1 $aCOSTA, P. B. 700 1 $aGILES, A. L. 700 1 $aSOSA, A. I. 700 1 $aCOUGHLIN, I. 700 1 $aGODLEE, J. L. 700 1 $aVASCONCELOS, S. S. 700 1 $aS. JUNIOR, J. A. 700 1 $aFERREIRA, L. V. 700 1 $aMENCUCCINI, M. 700 1 $aMEIR, P. 773 $tNew Phytologist$gv. 218, n. 4, p. 1393-1405, June 2018.
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