Data/hora: 16/06/2024 18:11:31

Biblioteca(s): | Embrapa Pantanal.
Data corrente: | 11/09/1997
Data da última atualização: | 05/04/2017
Autoria: | PERRY, D. A.; BORCHERS, J. G.; TURNER, D. P.; GREGORY, S. V.; PERRY, C. R.; DIXON, R. K.; HART, S. C.; KAUFFMAN, B.; NEILSON, R. P.; SOLLINS, P.
Título: | Biological feebacks to climate change: terrestrial ecosystems as sinks and sources of carbon and nitrogen.
Ano de publicação: | 1991
Fonte/Imprenta: | Northwest Environmental Journal, v.7, n.2, p.203-232, 1991.
Idioma: | Inglês
Conteúdo: | The major effect of vegetation on carbon fluxes to and from the atmosphere will be reorganization and redistribution of forests due to disturbance and migration. Because they store the bulk of terrestrial carbon, forests will play a key role. Boreal forests could extend onto current tundra, but only if precipitation increases enough to balance increased evapotranspiration. No plants excep weeds are likely to migrate fast enough to keep pace with climate change. Should frequency and severity of fire increase, as is predicted, northern forests are likely to become a source of CO2 to the atmosphere rather than a sink. Some models predict that tropical forests will expand, in which case they would be a strong sink for CO2; other models predict they will contract. However, when land-use practices are taken into account, tropical forests doubtless will contract regardless of wat happens with climate. Hence the tropics are much more lokely to be a CO2 sourcea rather than a sink. In terms of carbon fluxes, changes in terrestrial vegetation are more likely to significantly reinforce the greenhouse effect than to dampen it. The nitrogen released from accelerated decomposition of soil organic matter might stimulate forest productivity somewhat, but several lines of argument suggest that will not provide a significant negative feedback to warming. Amounts of nitrogen leached to streams could increase several-fold, increasing stream productivity. Should mountain forests become severely streassed, the resulting erosion would greatly increase sedimentation os stremas, rivers, and stuaries. Because the global ecosystem is complex, unpredicable, and subject to threshold changes that could be difficult or impossible to reverse, a "wait and see" attitude is not an appropriate response to impending climate change.
Palavras-Chave: | Biological feedback; Dreno e fonte de carbono e nitrogenio; Ecofisiologia vegetal; Sinks and source of carbon and nitrogen.
Thesagro: | Mudança Climática.
Thesaurus Nal: | climate change.
Categoria do assunto: | --
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (34837-1) - ADC - SP - PP - SP15378 -  - 15378 - DIS