期刊
ECOSYSTEMS
卷 11, 期 8, 页码 1352-1367出版社
SPRINGER
DOI: 10.1007/s10021-008-9198-0
关键词
soil CO2 efflux; temperature; moisture; gross primary productivity; leaf area index; soil carbon; land use
类别
资金
- EU FP5 projects CarboMont [EVK-2001-00125]
- GreenGrass [EVK-2001-00105]
- Austrian National Science Fund (FWF) [P18756-B16]
- Natural Environment Research Council [ceh010023] Funding Source: researchfish
- Austrian Science Fund (FWF) [P18756] Funding Source: Austrian Science Fund (FWF)
Soil respiration constitutes the second largest flux of carbon (C) between terrestrial ecosystems and the atmosphere. This study provides a synthesis of soil respiration (R-s) in 20 European grasslands across a climatic transect, including ten meadows, eight pastures and two unmanaged grasslands. Maximum rates of R-s (R-smax), R-s at a reference soil temperature (10 degrees C; R-s10) and annual R-s (estimated for 13 sites) ranged from 1.9 to 15.9 mu mol CO2 m(-2) s(-1), 0.3 to 5.5 mu mol CO2 m(-2) s(-1) and 58 to 1988 g C m(-2) y(-1), respectively. Values obtained for Central European mountain meadows are amongst the highest so far reported for any type of ecosystem. Across all sites Rsmax was closely related to R-s10.Assimilate supply affected R-s at timescales from daily (but not necessarily diurnal) to annual. Reductions of assimilate supply by removal of aboveground biomass through grazing and cutting resulted in a rapid and a significant decrease of R-s. Temperature-independent seasonal fluctuations of Rs of an intensively managed pasture were closely related to changes in leaf area index (LAI). Across sites R-s10 increased with mean annual soil temperature (MAT), LAI and gross primary productivity (GPP), indicating that assimilate supply overrides potential acclimation to prevailing temperatures. Also annual R-s was closely related to LAI and GPP. Because the latter two parameters were coupled to MAT, temperature was a suitable surrogate for deriving estimates of annual R-s across the grasslands studied. These findings contribute to our understanding of regional patterns of soil C fluxes and highlight the importance of assimilate supply for soil CO2 emissions at various timescales.
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