Nitrogen availability and precipitation variability regulated CO2 fertilization effects on carbon fluxes in an alpine grassland

doi:10.1016/j.agrformet.2021.108524

	Nitrogen availability and precipitation variability regulated CO2 fertilization effects on carbon fluxes in an alpine grassland
	Chen, Yao 7,8; Zhang, Yangjian 1,2,7; Chen, Ning 3; Cong, Nan 7; Zhu, Juntao 7; Zhao, Guang 7; Zu, Jiaxing 4,5; Liu, Yaojie 6; Zhu, Yixuan 7,8; Zheng, Zhoutao 7
刊名	AGRICULTURAL AND FOREST METEOROLOGY
	2021-09-15
卷号	307 页码:10
关键词	Ecosystem carbon fluxes Elevated CO2 Nitrogen addition Precipitation variability Leaf nitrogen concentration Tibetan plateau
ISSN号	0168-1923
DOI	10.1016/j.agrformet.2021.108524
通讯作者	Zhang, Yangjian(zhangyj@igsnrr.ac.cn) ; Zhao, Guang(zhaoguang@igsnrr.ac.cn)
英文摘要	It's generally believed that elevated CO2 (eCO(2)) could stimulate plant growth and the ecosystem carbon (C) sink. However, great uncertainties exist in terms of the CO2 fertilization effect (CFE) magnitude, and how it is regulated by other global change factors. The lack of experimental evidence from the Alpine Region also limits our cognition on the CFE. By conducting a five-year manipulative field experiment in a semi-arid grassland of the Tibetan Plateau, we are aimed to explore the behavior of ecosystem C exchange in response to eCO(2) and N availability under contrasting natural precipitation regimes. The experiment showed that eCO(2) stimulated both gross ecosystem productivity (GEP) and ecosystem respiration (ER), and resulted in a neutral effect on net ecosystem productivity (NEP). The reduction of leaf N concentration under eCO(2) constrained the eCO(2) effects on C fluxes, especially on GEP and NEP. As N addition replenishes N availability in soil and leaf, GEP benefited more from the N addition than the ER. The eCO(2) strengthened the C sink when exogenous N was added simultaneously. Furthermore, precipitation variability played an importance role in mediating the eCO(2) effect among growing seasons. The eCO(2) effects on C fluxes tended to decline with increased water availability. The CFE was suppressed with excessive precipitation when the water-use efficiency (WUE) response was weak and eCO(2)-induced water-saving disappeared. The negative impact of precipitation on the CFE may also be attributed to the short precipitation intervals and insufficient radiation caused by high-frequency precipitation. Our study demonstrates that eCO(2) only stimulates net C uptake under conditions of N addition or during drier periods. Given the widespread N limitation, the efficacy of terrestrial ecosystems in mitigating climate change under rising CO2 may be weaker than projected and is closely related to the precipitation variability.
资助项目	Second Tibetan Plateau Scientific Expedition and Research (STEP) program[2019QZKK0302] ; National Natural Science Foundation of China[41725003]
WOS关键词	ELEVATED ATMOSPHERIC CO2 ; PLANT WATER RELATIONS ; STOMATAL CONDUCTANCE ; ECOSYSTEM CARBON ; GROWTH-RESPONSE ; SOIL ; FOREST ; PHOTOSYNTHESIS ; PRODUCTIVITY ; RESPIRATION
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000682515100038
资助机构	Second Tibetan Plateau Scientific Expedition and Research (STEP) program ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/164651]
专题	中国科学院地理科学与资源研究所
通讯作者	Zhang, Yangjian; Zhao, Guang
作者单位	1.CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China 2.Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100190, Peoples R China 3.Chinese Acad Sci, Northeast Inst Geog & Agroecol, Key Lab Wetland Ecol & Environm, Changchun 130102, Peoples R China 4.Nanning Normal Univ, Guangxi Key Lab Earth Surface Proc & Intelligent, Nanning 530001, Peoples R China 5.Nanning Normal Univ, Minist Educ, Key Lab Environm Change & Resources Use Beibu Gul, Nanning 530001, Peoples R China 6.Nanjing Univ, Int Inst Earth Syst Sci, Nanjing 210093, Peoples R China 7.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing 100101, Peoples R China 8.Univ Chinese Acad Sci, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Chen, Yao,Zhang, Yangjian,Chen, Ning,et al. Nitrogen availability and precipitation variability regulated CO2 fertilization effects on carbon fluxes in an alpine grassland[J]. AGRICULTURAL AND FOREST METEOROLOGY,2021,307:10.
APA	Chen, Yao.,Zhang, Yangjian.,Chen, Ning.,Cong, Nan.,Zhu, Juntao.,...&Tang, Ze.(2021).Nitrogen availability and precipitation variability regulated CO2 fertilization effects on carbon fluxes in an alpine grassland.AGRICULTURAL AND FOREST METEOROLOGY,307,10.
MLA	Chen, Yao,et al."Nitrogen availability and precipitation variability regulated CO2 fertilization effects on carbon fluxes in an alpine grassland".AGRICULTURAL AND FOREST METEOROLOGY 307(2021):10.