气候变化领域集成服务门户(CCPortal): Increased precipitation offsets the negative effect of warming on plant biomass and ecosystem respiration in a Tibetan alpine steppe

CCPortal

DOI	10.1016/j.agrformet.2019.107761
	Increased precipitation offsets the negative effect of warming on plant biomass and ecosystem respiration in a Tibetan alpine steppe
	Zhao Jingxue; Luo Tianxiang; Wei Haixia; Deng Zhaoheng; Li Xiang; Li Ruicheng; Tang Yanhong
通讯作者	Luo, TX (通讯作者)
发表日期	2019
ISSN	0168-1923
EISSN	1873-2240
卷号	279
英文摘要	The Tibetan Plateau has become warmer and wetter in recent decades, and the warming of more than 2 degrees C has been considered as a risk threshold that may lead to irreversible changes in arid and semi-arid grassland ecosystems. However, few data have examined the extent to which the projected increase of precipitation may offset the negative effect of 2 degrees C warming on aboveground biomass (AGB) and ecosystem respiration (Re) in the vast alpine grasslands. We conducted a field manipulative experiment to investigate the combined effects of 2 degrees C warming plus 15% and 30% increased precipitation on AGB and Re in an alpine steppe. We observed vegetation cover, AGB, Re, soil temperature (ST), soil moisture (SM), and soil organic carbon (SOC) in the growing seasons of 2013 and 2014. Thornthwaite moisture index (MI) in the growing season (May-September) was calculated for each experimental treatment. Experimental warming generally increased ST and reduced SM and MI, and consequently caused significant reductions in vegetation cover, AGB and Re. Increased precipitation typically stimulated AGB and Re. Compared to the control, relative changes in AGB and Re increased from a negative value under warming with ambient precipitation to a positive value under warming plus 15% and 30% increased precipitation. In pooled data across treatments and years, the changes of AGB and Re showed a positive linear relation to the warming/watering induced variation of MI. The structural equation modeling indicated that AGB and SM rather than ST and SOC were the major factors driving Re during the growing season. In addition, experimental warming decreased the temperature sensitivity of Re (Q(10)), whereas increased precipitation had a positive effect on Q(10). Our data demonstrate that the water deficit induced by 2 degrees C warming and its negative effect on AGB and Re can be offset by >15% increased precipitation in a semi-arid alpine grassland on the Tibetan Plateau. The change in balance of precipitation and evapotranspiration is an ecologically meaningful metric for generally describing the spatiotemporal variability of soil water availability and ecosystem function under climate change.
关键词	LARGE ALTITUDINAL GRADIENT CLIMATE-CHANGE SOIL RESPIRATION TERRESTRIAL ECOSYSTEMS CARBON FLUXES TEMPERATURE SENSITIVITY WATER AVAILABILITY MEADOW PLATEAU GRASSLAND
英文关键词	Climate change; Plant biomass; Carbon cycles; Alpine grasslands; Tibetan Plateau
语种	英语
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
WOS类目	Agronomy ; Forestry ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000500197400046
来源期刊	AGRICULTURAL AND FOREST METEOROLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259516
推荐引用方式 GB/T 7714	Zhao Jingxue,Luo Tianxiang,Wei Haixia,et al. Increased precipitation offsets the negative effect of warming on plant biomass and ecosystem respiration in a Tibetan alpine steppe[J]. 中国科学院青藏高原研究所,2019,279.
APA	Zhao Jingxue.,Luo Tianxiang.,Wei Haixia.,Deng Zhaoheng.,Li Xiang.,...&Tang Yanhong.(2019).Increased precipitation offsets the negative effect of warming on plant biomass and ecosystem respiration in a Tibetan alpine steppe.AGRICULTURAL AND FOREST METEOROLOGY,279.
MLA	Zhao Jingxue,et al."Increased precipitation offsets the negative effect of warming on plant biomass and ecosystem respiration in a Tibetan alpine steppe".AGRICULTURAL AND FOREST METEOROLOGY 279(2019).