Data/hora: 25/06/2024 18:12:41

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	04/05/2001	
Data da última atualização: 	30/03/2017	
Autoria: 	CONANT, R. T.; KLOPATEK, J. M.; KLOPATEK, C. C.	
Título: 	Environmental factors controlling soil respiration in three semiarid ecosystem.	
Ano de publicação: 	2000	
Fonte/Imprenta: 	Soil Science Society of America Journal, v.64, n.1, p.383-390, 2000.	
Idioma: 	Inglês	
Conteúdo: 	Previous research suggests that soil organic C pools may be a feature of semiarid regions that are particularly sensitive to climatic changes. we instituted an 18-mo experiment along an elevation gradient in northern arizona to evaluate the influence of temperature, moisture, and soil C pool size on soil respiration. Soils, from underneath different tree canopy types and interspaces of three semiarid ecosystems, were moved upslope and/or downslope to modify soil climate. Soils moved downslope experienced increased temperature and decreased precipitation, resulting in decreased soil moisture and soil respiration (as much as 23 and 20%, respectively). Soils moved upslope to more mesic, cooler sites had greather soil water content and increase rates of soil respiration (as much as 40%), despite decreased temperature. Soil respiration rates normalized for total C were not significantly different within any of the three incubations sites, indicating that under identical climatic conditions, soil respiration is directly related to soil C pool size for the incubated soils. Normalized soil respiration rates between sites differed significantly for all soil types and were always greather for soils incubated under more mesic, but cooler, conditions. Total soil C did not change significantly during the experiment, but estimates suggest that significant portions of the rapidly cycling C pool were lost. While long-term decreases in aboveground and belowground detrital inputs may ultimately be greater than decreased soil respiration, the initial response to increased temperature and decreased precipitation in these systems is a decrease in annual soil C efflux.	
Palavras-Chave: 	Ecosystem; Semi-arid; Semi-arido.	
Thesagro: 	Ecossistema; Meio Ambiente; Solo.	
Thesaurus Nal: 	environment; soil.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (48957-1) - ADC - SP - PP - SP16247 -  - 16247 - DIS