Vulnerability of soil organic matter to temperature increase / Vulnerabilidade da matéria orgânica do solo ao aumento de temperatura

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Soil organic matter (SOM) decomposition emits greenhouse gases to the atmosphere and this may contribute to global warming. Global warming can promote a positive feedback on SOM decomposition rate and it can increase soil C losses. The SOM has different pools with inherent temperature sensitivity. Some researches suggest that resistant soil C is less sensitive to temperature increase. Moreover, there are some physical, chemical and biochemical mechanisms that protect SOM against decomposition. The global warming may change the soil microbial structure and it can modify SOM decomposition. In Brazil, the greenhouse gas emissions are basically driven by the land use change. The substitution of native vegetation (forest) to pasture changes soil C signature - 13C and this fact enable us to study the source of soil C emissions. The objective of this study was to evaluate the SOM vulnerability to temperature increased. Forest and pastures soil samples were incubated under 25 and 35 ºC. The labile-C versus resistant-C temperature sensitivity was evaluated and the SOM protection mechanisms were studied to understand how they can protect SOM against decomposition.

ASSUNTO(S)

matéria orgânica do solo solos florestais desmatamento aquecimento global co2 emissions global warming deforestation pastagens soil carbon gás carbônico - emissão temperatura. amazônia amazon.

Documentos Relacionados