文献类型：期刊文献

英文题名：Nonlinear carbon cycling responses to precipitation variability in a semiarid grassland

作者：Li, Linfeng[1,2] Kang, Xiaoming[3,4,5] Biederman, Joel A.[6] Wang, Weijin[2,7] Qian, Ruyan[8] Zheng, Zhenzhen[8] Zhang, Biao[1] Ran, Qinwei[8] Xu, Cong[9] Liu, Wenjun[10] Che, Rongxiao[11] Xu, Zhihong[2] Cui, Xiaoyong[8,12,13] Hao, Yanbin[8,12,13] Wang, Yanfen[8,12,13]

第一作者：Li, Linfeng

通信作者：Hao, YB[1]

机构：[1]Univ Chinese Acad Sci, Coll Resources & Environm, Beijing 100049, Peoples R China;[2]Griffith Univ, Sch Environm & Sci, Environm Futures Res Inst, Brisbane, Qld 4111, Australia;[3]Chinese Acad Forestry, Inst Wetland Res, Beijing 100091, Peoples R China;[4]Beijing Key Lab Wetland Serv & Restorat, Beijing 100091, Peoples R China;[5]Tibetan Autonomous Prefecture Aba, Sichuan Zoige Wetland Ecosyst Res Stn, Beijing 624500, Peoples R China;[6]ARS, Southwest Watershed Res Ctr, Tucson, AZ 85719 USA;[7]Univ Queensland, Sch Agr & Food Sci, Brisbane, Qld 4072, Australia;[8]Univ Chinese Acad Sci, Coll Life Sci, Beijing 100049, Peoples R China;[9]Chinese Acad Sci, Aerosp Informat Res Inst, State Key Lab Remote Sensing Sci, Beijing 100101, Peoples R China;[10]Yunnan Univ, Sch Ecol & Environm Sci, Kunming 650091, Yunnan, Peoples R China;[11]Yunnan Univ, Inst Int Rivers & Ecosecur, Kunming 650091, Yunnan, Peoples R China;[12]Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100101, Peoples R China;[13]Univ Chinese Acad Sci, Chinese Acad Sci, Yanshan Earth Crit Zone & Surface Fluxes Res Stn, Beijing 10049, Peoples R China

年份：2021

卷号：781

外文期刊名：SCIENCE OF THE TOTAL ENVIRONMENT

收录：;EI(收录号：20211610236757);Scopus(收录号：2-s2.0-85104280787);WOS:【SCI-EXPANDED(收录号:WOS:000655621600007)】；

基金：This project was funded by the CAS Strategic Priority Research Programme (A) (Grant No. XDA20050103, XDA19030202) and the International Cooperation and Exchange of National Natural Science Foundation of China (Grant No. 31761123001, 31761143018) . J. Biederman's contributions were supported by the U.S. Department of Agriculture, Agricultural Research Service. USDA is an equalopportunity employer. Great thanks for the help of the Inner Mongolia Grassland Ecosystem Research Station.

语种：英文

外文关键词：Altered precipitation; Carbon-nitrogen-water coupling; Climate extremes; Nonlinear responses; Resource variability; Semiarid steppe

摘要：Changes in precipitation amount and variability would profoundly affect carbon (C) cycling in arid and semiarid grasslands. However, compared to the effects of precipitation amounts, little is understood about the impacts of precipitation temporal variability on terrestrial C cycling. To explore relationships between precipitation variability and C cycling processes and the underlying mechanisms, we conducted a 3-year field experiment and a 12-year model simulation, in which the constant seasonal precipitation amount was temporally manipulated with four and six levels of precipitation variability, respectively, in a semiarid grassland. Based on the manipulative experiment, we found various nonlinear relationships between C cycling processes and the coefficient of precipitation variability (P-cv), including a trinomial relationship for soil respiration (tipping point: 3 and 4.3), convex relationships for gross and net ecosystem production (peak at 3.5) as well as belowground biomass (peak at 4) and a nonlinear negative relationship for ecosystem respiration (peak at 2.5). Such relationships were regulated by seasonal averaged soil water content (SWC), early-growing season precipitation amount, soil inorganic nitrogen availability (SIN), and both SWC and SIN, respectively. However, these results from the manipulative experiment did not match those from the model simulation, in which ecosystem C cycling processes, dominated only by SWC responses, showed positive linear responses to P-cv. Our results mirror that the nonlinear responses of grassland C cycling to precipitation variability as regulate by SWC and SIN should be incorporated into models to forecast future ecosystem shifts under climate change. (C) 2021 Elsevier B.V. All rights reserved.