干旱区生态环境知识资源中心(Arid): Contrary responses of soil heterotrophic and autotrophic respiration to spring and summer drought in alfalfa on the Loess Plateau

Arid

DOI	10.1016/j.geoderma.2023.116722
	Contrary responses of soil heterotrophic and autotrophic respiration to spring and summer drought in alfalfa on the Loess Plateau
	Chu, Houkun; Ni, Hong; Ma, Jingyong; Shen, Yuying
通讯作者	Shen, YY
来源期刊	GEODERMA
ISSN	0016-7061
EISSN	1872-6259
出版年	2023
卷号	440
英文摘要	Climate change has increased the intensity and frequency of seasonal droughts, which could fundamentally affect the terrestrial carbon (C) cycle. However, as the second-largest terrestrial C flux, soil respiration (Rs) and its heterotrophic (Rh) and autotrophic (Ra) components in response to seasonal drought are unclear. To investigate the effect of seasonal drought on the patterns and mechanisms of Rs and its components, a two-year continuous Rs measurement experiment was conducted in typical rain-fed managed alfalfa (Medicago sativa L.) fields on the Loess Plateau in China. The results showed that the ranges of Rs, Rh and Ra in the four seasons of managed alfalfa fields on the Loess Plateau were 0.45-3.70, 0.13-2.27, and 0.33-2.14 mu mol m(-2) s(-1), respectively. There was no significant difference in the average annual Rs between the two years (P > 0.05). Both spring and summer droughts significantly decreased Rs; however, the seasonal Rh and Ra had different patterns under spring and summer droughts. Spring drought significantly reduced the seasonal Rh by 35.19 % but increased Ra by 20.35 %. In contrast, summer drought significantly increased the seasonal Rh by 45.51 % but decreased the Ra by 35.05 %. The differential response of Ra to seasonal drought was attributed to the opposite responses of the leaf area index (LAI) and photosynthetic rate to spring and summer drought, while Rh was related to the contrasting microorganism responses to spring drought and the pulse effect of rainfall following summer drought. Our study highlights the contrasting responses of Ra and Rh to seasonal drought. Spring drought significantly reduced the relative contribution of Rh to Rs, but summer drought increased the relative contribution of Rh to Rs. These results suggest that future increases in the frequency of summer droughts may accelerate the turnover of soil C and further affect the stability of soil C stocks in semi-arid regions.
英文关键词	Drought Soil respiration Autotrophic respiration Heterotrophic respiration Carbon cycle
类型	Article
语种	英语
开放获取类型	hybrid
收录类别	SCI-E
WOS记录号	WOS:001130451200001
WOS关键词	CO2 EFFLUX ; PRODUCTIVITY ; TEMPERATURE ; COMPONENTS ; NITROGEN ; IMPACTS ; WATER ; ROOT
WOS类目	Soil Science
WOS研究方向	Agriculture
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/396702
推荐引用方式 GB/T 7714	Chu, Houkun,Ni, Hong,Ma, Jingyong,et al. Contrary responses of soil heterotrophic and autotrophic respiration to spring and summer drought in alfalfa on the Loess Plateau[J],2023,440.
APA	Chu, Houkun,Ni, Hong,Ma, Jingyong,&Shen, Yuying.(2023).Contrary responses of soil heterotrophic and autotrophic respiration to spring and summer drought in alfalfa on the Loess Plateau.GEODERMA,440.
MLA	Chu, Houkun,et al."Contrary responses of soil heterotrophic and autotrophic respiration to spring and summer drought in alfalfa on the Loess Plateau".GEODERMA 440(2023).