Soil moisture, species composition interact to regulate CO2 and CH4 fluxes in dry meadows on the Tibetan Plateau

doi:10.1016/j.ecoleng.2016.02.012

	Soil moisture, species composition interact to regulate CO2 and CH4 fluxes in dry meadows on the Tibetan Plateau
	Luan, JW; Song, HT; Xiang, CH; Zhu, D; Suolang, D; Luan, JW (reprint author), Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China.; Luan, JW (reprint author), Mem Univ Newfoundland, Sustainable Resource Management, Grenfell Campus, Corner Brook, ON A2H 5G4, Canada.
刊名	ECOLOGICAL ENGINEERING
	2016
卷号	91 页码:101-112
关键词	Carbon Sequestration Neemethanegrass Land Degradation Drought Plant Community Compositiona
DOI	10.1016/j.ecoleng.2016.02.012
产权排序	4
文献子类	Article
英文摘要	Alpine meadows on the Tibetan Plateau are important sinks for atmosphere carbon (C). Environmental degradation is transforming the continuous sedge (e.g., Kobresia humilis) meadows into a mosaic of sedge and forb-dominated (e.g., Potentilla leuconota) patches, and this provides an ideal system in which to examine how the change in species composition (from sedge-to forb-dominated) affects the CO2 and CH4 fluxes and their response to environmental change. Net ecosystem CO2 exchange (NEE), ecosystem respiration (R-eco), and methane (CH4) fluxes were measured monthly both in sedge- and forb-dominated patches during the growing seasons of 2011 and 2012. The seasonal variations of NEE (negative values represent net uptake of CO2) were negatively affected by soil water content (SWC) both in the sedge (R = -0.46, P=0.02) and in the forb (R = -0.71, P < 0.001) sites, and the SWC regulated the NEE through exerting influence on gross ecosystem photosynthesis (GEP) (P < 0.001) rather than on R-eco (P>0.1). The CH4 fluxes were positively correlated with SWC for both sedge (R = 0.48, P = 0.016) and forb sites (R = 0.70, P < 0.001). Nevertheless, the CH4 emission can offset only 0.05% of the net C uptake as a result of the increase in SWC. Change in species composition did not affect the rates in NEE, R-eco, and GEP (P > 0.05); however, it led to the NEE of the meadow being more sensitive to SWC change (P=0.042). Change in species composition significantly reduced the CH4 flux (P=0.05), which were attributed to the decrease in soil labile carbon (e.g., microbial biomass carbon) and soil enzymatic activity (e.g., protease and urease). However, it increased the soil moisture sensitivity of CH4 flux (P=0.033). We conclude that the C sink strength of the alpine dry meadow is subject to the change in soil water availability on the Plateau, and the alpine meadow will become more vulnerable to drought with the ongoing spread of forb-dominated patches. Our results highlight the role of species composition in regulating the response of the alpine meadow C cycle to environmental change. (C) 2016 Elsevier B.V. All rights reserved.
学科主题	Environmental Sciences & Ecology ; Engineering
资助项目	Luan, Junwei/0000-0002-3848-4747
项目编号	Luan, Junwei/E-2706-2017
语种	英语
资助机构	National Natural Science Foundation of China [31200370] ; National Natural Science Foundation of China [31200370] ; Research Institute of Forestry New Technology [CAFINT2011C09] ; Research Institute of Forestry New Technology [CAFINT2011C09] ; Chinese Ministry of Finance [201204201] ; Chinese Ministry of Finance [201204201] ; National Natural Science Foundation of China [31200370] ; National Natural Science Foundation of China [31200370] ; Research Institute of Forestry New Technology [CAFINT2011C09] ; Research Institute of Forestry New Technology [CAFINT2011C09] ; Chinese Ministry of Finance [201204201] ; Chinese Ministry of Finance [201204201]
内容类型	期刊论文
源URL	[http://210.75.237.14/handle/351003/28124]
专题	成都生物研究所_生态研究
通讯作者	Luan, JW (reprint author), Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China.; Luan, JW (reprint author), Mem Univ Newfoundland, Sustainable Resource Management, Grenfell Campus, Corner Brook, ON A2H 5G4, Canada.
推荐引用方式 GB/T 7714	Luan, JW,Song, HT,Xiang, CH,et al. Soil moisture, species composition interact to regulate CO2 and CH4 fluxes in dry meadows on the Tibetan Plateau[J]. ECOLOGICAL ENGINEERING,2016,91:101-112.
APA	Luan, JW.,Song, HT.,Xiang, CH.,Zhu, D.,Suolang, D.,...&Luan, JW .(2016).Soil moisture, species composition interact to regulate CO2 and CH4 fluxes in dry meadows on the Tibetan Plateau.ECOLOGICAL ENGINEERING,91,101-112.
MLA	Luan, JW,et al."Soil moisture, species composition interact to regulate CO2 and CH4 fluxes in dry meadows on the Tibetan Plateau".ECOLOGICAL ENGINEERING 91(2016):101-112.