干旱区生态环境知识资源中心(Arid): Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region

Arid

	Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region
	Ma Jie; Liu Ran; Li Yan
来源期刊	Journal of Arid Land
ISSN	1674-6767
出版年	2017
卷号	9 期号:1 页码:13-26
英文摘要	As an important component of ecosystem carbon (C) budgets, soil carbon dioxide (CO_2) flux is determined by a combination of a series of biotic and abiotic processes. Although there is evidence showing that the abiotic component can be important in total soil CO_2 flux (R_(total)), its relative importance has never been systematically assessed. In this study, after comparative measurements of CO_2 fluxes on sterilized and natural soils, the R_(total) was partitioned into biotic flux (R_(biotic)) and abiotic flux (R_(abiotic)) across a broad range of land-cover types (including eight sampling sites: cotton field, hops field, halophyte garden, alkaline land, reservoir edge, native saline desert, dune crest and interdune lowland) in Gurbantunggut Desert, Xinjiang, China. The relative contribution of R_(abiotic) to R_(total), as well as the temperature dependency and predominant factors for R_(total), R_(biotic) and R_(abiotic), were analyzed. Results showed that R_(abiotic) always contributed to R_(total) for all of the eight sampling sites, but the degree or magnitude of contribution varied greatly. Specifically, the ratio of R_(abiotic) to R_(total) was very low in cotton field and hops field and very high in alkaline land and dune crest. Statistically, the ratio of R_(abiotic) to R_(total) logarithmically increased with decreasing R_(biotic), suggesting that R_(abiotic) strongly affected R_(total) when R_(biotic) was low. This pattern confirms that soil CO_2 flux is predominated by biotic processes in most soils, but abiotic processes can also be dominant when biotic processes are weak. On a diurnal basis, R_(abiotic) cannot result in net gain or net loss of CO_2, but its effect on transient CO_2 flux was significant. Temperature dependency of R_(total) varied among the eight sampling sites and was determined by the predominant processes (abiotic or biotic) of CO_2 flux. Specifically, R_(biotic) was driven by soil temperature while R_(abiotic) was regulated by the change in soil temperature (DeltaT). Namely, declining temperature (DeltaT<0) resulted in negative R_(abiotic) (i.e., CO_2 went into soil) while rising temperature (DeltaT>0) resulted in positive R_(abiotic) (i.e., CO_2 released from soil). Without recognition of R_(abiotic), R_(biotic) would be overestimated for the daytime and underestimated for the nighttime. Although R_(abiotic) may not change the sum or the net value of daily soil CO_2 exchange and may not directly constitute a C sink, it can significantly alter the transient apparent soil CO_2 flux, either in magnitude or in temperature dependency. Thus, recognizing the fact that abiotic component in R_(total) exists widely in soils has widespread consequences for the understanding of C cycling.
英文关键词	soil CO_2 flux biotic flux abiotic flux temperature dependence Gurbantunggut Desert
类型	Article
语种	英语
开放获取类型	Bronze
收录类别	CSCD
WOS研究方向	Agriculture
CSCD记录号	CSCD:5905887
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335746
作者单位	Ma Jie, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, State Key Laboratory of Desert and Oasis Ecology, Urumqi, Xinjiang 830011, China.; Liu Ran, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, State Key Laboratory of Desert and Oasis Ecology, Urumqi, Xinjiang 830011, China.; Li Yan, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, State Key Laboratory of Desert and Oasis Ecology, Urumqi, Xinjiang 830011, China.
推荐引用方式 GB/T 7714	Ma Jie,Liu Ran,Li Yan. Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region[J],2017,9(1):13-26.
APA	Ma Jie,Liu Ran,&Li Yan.(2017).Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region.Journal of Arid Land,9(1),13-26.
MLA	Ma Jie,et al."Abiotic contribution to total soil CO_2 flux across a broad range of land-cover types in a desert region".Journal of Arid Land 9.1(2017):13-26.