DOI: 10.1007/s10533-013-9881-x
Scopus记录号: 2-s2.0-84897405549
论文题名: Experimental summer drought reduces soil CO2 effluxes and DOC leaching in Swiss grassland soils along an elevational gradient
作者: Hagedorn F. ; Joos O.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 117, 期: 2018-02-03 起始页码: 395
结束页码: 412
语种: 英语
英文关键词: Altitude
; Climate change
; Dissolved organic carbon
; Drought
; Litter decomposition
; Soil moisture
; Soil organic carbon
; Soil respiration
; Temperature
Scopus关键词: altitude
; carbon balance
; carbon dioxide
; carbon isotope
; climate change
; dissolved organic carbon
; drought stress
; experimental study
; grassland
; leaching
; precipitation (climatology)
; soil carbon
; soil emission
; soil respiration
; soil temperature
; topsoil
; Switzerland
英文摘要: Soil moisture affects belowground activity in grasslands, but the effects of summer drought on different soil C fluxes is uncertain. Soil respiration (SR), dissolved organic carbon (DOC) leaching and their components may all respond differently and drought effects will interact with other factors such as temperature, making a priori predictions of soil C balances difficult. In this study, we used rain shelters to simulate summer droughts by reducing annual precipitation by around 30 % in three managed grassland sites at 400, 1,000 and 2,000 m a.s.l. in Switzerland covering a gradient in mean annual temperatures of 7.5 °C. During the growing season, we quantified the impacts of drought on SR, DOC leaching, litter decomposition and the contribution of 13C-depleted litter to DOC fluxes. Along the elevational gradient, SR rates did not decrease with increasing altitude. Thus, SR was higher at a given temperature at higher altitudes, which probably reflects more labile soil C and hence greater substrate availability in a colder climate. Fluxes of DOC at 5 cm depth were a magnitude smaller than SR and did not show a pattern with elevation. At all altitudes, the experimental summer drought significantly reduced SR rates by 25-57 % and DOC leaching by 80-100 %, with a declining contribution of 13C-depleted litter-DOC. The remaining litter mass after drought was two to seven times larger as compared to the control. We did not observe a strong C release upon rewetting and hence, there was no compensation for the reduced soil C fluxes during drought. The more sensitive drought response in the litter layer than in the deeper soil and the declining DOC fluxes indicate an altered soil C balance with a C preservation in the topsoil, but ongoing losses of probably 'older' C in subsoils under drought. © 2013 Springer Science+Business Media Dordrecht. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83628
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Department of Geography, University of Zurich, Zurich, Switzerland
Recommended Citation:
Hagedorn F.,Joos O.. Experimental summer drought reduces soil CO2 effluxes and DOC leaching in Swiss grassland soils along an elevational gradient[J]. Biogeochemistry,2014-01-01,117(2018-02-03)