title: Severe summer heatwave and drought strongly reduced carbon uptake in Southern China.
abstract: Increasing heatwave and drought events can potentially alter the carbon cycle. Few studies have investigated the impacts of hundred-year return heatwaves and droughts, as those events are rare. In the summer of 2013, southern China experienced its strongest drought and heatwave on record for the past 113 years. We show that the record-breaking heatwave and drought lasted two months (from July to August), significantly reduced the satellite-based vegetation index and gross primary production, substantially altered the regional carbon cycle, and produced the largest negative crop yield anomaly since 1960. The event resulted in a net reduction of 101.54 Tg C in carbon sequestration in the region during these two months, which was 39-53% of the annual net carbon sink of China's terrestrial ecosystems (190-260 Tg C yr(-1)). Moreover, model experiments showed that heatwaves and droughts consistently decreased ecosystem vegetation primary production but had opposite impacts on ecosystem respiration (TER), with increased TER by 6.78 ± 2.15% and decreased TER by 15.34 ± 3.57% assuming only changed temperature and precipitation, respectively. In light of increasing frequency and severity of future heatwaves and droughts, our study highlights the importance of accounting for the impacts of heatwaves and droughts in assessing the carbon sequestration in terrestrial ecosystems.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.|State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China.
authors.forename: Wenping
authors.initials: W
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Wenwen
authors.initials: W
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.affiliation: National Engineering Laboratory for Applied Technology of Forestry &Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
authors.forename: Shuguang
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Wenjie
authors.initials: W
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Haicheng
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Guirui
authors.initials: G
authors.lastname: Yu
authors.affiliation: College of Global Change and Earth System Science, Beijing Normal University, Beijing 100875, China.
authors.forename: Zhuoqi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Ecosystem Network Observation and Modeling, Synthesis Research Center of Chinese Ecosystem Research Network, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Honglin
authors.initials: H
authors.lastname: He
authors.affiliation: Institute for Climate and Global Change Research &School of Atmospheric Sciences, Nanjing University, China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Remote Sensing Science, School of Geography, Beijing Normal University, Beijing 100875, China.
authors.forename: Shaoming
authors.initials: S
authors.lastname: Liu
authors.affiliation: National Engineering Laboratory for Applied Technology of Forestry &Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: Xiang
authors.affiliation: State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhenghui
authors.initials: Z
authors.lastname: Xie
authors.affiliation: National Engineering Laboratory for Applied Technology of Forestry &Ecology in South China, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
authors.forename: Zhonghui
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Zhejiang Agriculture and Forestry University, Lin'an 311300, China.
authors.forename: Guomo
authors.initials: G
authors.lastname: Zhou
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D057965:Carbon Sequestration; D002681:China; D018556:Crops, Agricultural / Q000254:growth & development; D055864:Droughts; D017753:Ecosystem; D006358:Hot Temperature; D011891:Rain; D063809:Satellite Imagery; D012621:Seasons
chemical_list: D002245:Carbon Dioxide