气候变化领域集成服务门户(CCPortal): Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem

CCPortal

DOI	10.1016/j.agrformet.2020.108254
	Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem
	Sun S.; Che T.; Gentine P.; Chen Q.; Wang L.; Yan Z.; Chen B.; Song Z.
发表日期	2021
ISSN	1681923
卷号	297
英文摘要	Wet alpine meadows generally act as a significant carbon sink, since their low rate of soil decomposition determines a much smaller ecosystem respiration (Re) than photosynthesis. However, it remains unclear whether the low soil decomposition rate is determined by low temperatures or by nearly-saturated soil moisture. We explored this issue by using five years of measurements from two eddy-covariance sites with low temperature and significantly different soil water conditions. The results showed that both sites were carbon sinks. However, despite a smaller annual gross primary productivity, the wet site with a shallow groundwater showed a much higher carbon use efficiency and larger carbon sink than the dry site (which had a deeper water table) due to its much lower Re. Our analyses showed that Re of the wet site was significantly decreased under the nearly-saturated soil condition during the unfrozen seasons. This effect of nearly-saturated soil water on Re increased with soil depths. In contrast, at the dry site the high soil water content favored Re. The corresponding soil temperature at both sites expectedly showed large and positive effects on Re. These results demonstrated that the high carbon sink of the wet alpine meadow was mainly caused by the inhibiting effects of the nearly-saturated soil condition on soil respiration rather than by the low temperatures. Therefore, we argue that a warming-induced shrinking cryosphere may affect the carbon dynamics of wet and cold ecosystems through changes in soil hydrology and its impact on soil respiration. In addition, our study highlights the different responses of soil respiration to warming across soil depths. The thawing of frozen soil may cause larger CO2 emission in the top soil, while it may also partially contribute to slowing down soil carbon decomposition in the deep soil through decreasing metabolic activity of aerobic organisms. © 2020
英文关键词	alpine meadow; carbon exchange; frozen soil; soil respiration; Tibetan Plateau; water table level
语种	英语
scopus关键词	Agricultural and Forest Meteorology
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/158281
作者单位	Institute of Surface-Earth System Science; School of Earth System Science; Tianjin University; Tianjin; 300072; China; Tianjin Key Laboratory of Earth Critical Zone Science and Sustainable Development in Bohai Rim; Tianjin UniversityTianjin 300072; China; Heihe Remote Sensing Experimental Research Station; Northwest Institute of Eco-Environment and Resources; Chinese Academy of SciencesLanzhou 730000; China; Earth Institute; Columbia University; New York; 10027; United States; Department of Earth and Environmental Engineering; Columbia University; New York; 10027; United States; State Key Laboratory of Remote Sensing Science; Aerospace Information Research Institute; Chinese Academy of Sciences; Beijing; 100101; China; State Key Laboratory of Resources and Environment Information System; Institute of Geographic Sciences and Natural Resources Research; Chinese Academy of Sciences; Beijing; 100101; China
推荐引用方式 GB/T 7714	Sun S.,Che T.,Gentine P.,et al. Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem[J]. 中国科学院西北生态环境资源研究院,2021,297.
APA	Sun S..,Che T..,Gentine P..,Chen Q..,Wang L..,...&Song Z..(2021).Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem.,297.
MLA	Sun S.,et al."Shallow groundwater inhibits soil respiration and favors carbon uptake in a wet alpine meadow ecosystem".297(2021).