title: Comparison of the effects of symmetric and asymmetric temperature elevation and CO2 enrichment on yield and evapotranspiration of winter wheat (Triticum aestivum L.).
abstract: Under the changing climate, asymmetric warming pattern would be more likely during day and night time, instead of symmetric one. Concurrently, the growth responses and water use of plants may be different compared with those estimated based on symmetric warming. In this work, it was compared with the effects of symmetric (ETs) and asymmetric (ETa) elevation of temperature alone, and in interaction with elevated carbon dioxide concentration (EC), on the grain yield (GY) and evapotranspiration in winter wheat (Triticum aestivum L.) based on pot experiment in the North China Plain (NCP). The experiment was carried out in six enclosed-top chambers with following climate treatments: (1) ambient temperature and ambient CO2 (CON), (2) ambient temperature and elevated CO2 (EC), (3) elevated temperature and ambient CO2 (ETs; ETa), and (4) elevated temperature and elevated CO2 (ECETs, ECETa). In symmetric warming, temperature was increased by 3°C and in asymmetric one by 3.5°C during night and 2.5°C during daytime, respectively. As a result, GY was in ETa and ETs 15.6 (P < 0.05) and 10.3% (P < 0.05) lower than that in CON. In ECETs and ECETa treatments, GY was 14.9 (P < 0.05) and 9.1% (P < 0.05) higher than that in CON. Opposite to GY, evapotranspiration was 7.8 (P < 0.05) and 17.9% (P < 0.05) higher in ETa and ETs treatments and 7.2 (P < 0.05) and 2.1% (P > 0.05) lower in ECETs and ECETa treatments compared with CON. Thus, GY of wheat could be expected to increase under the changing climate with concurrent elevation of CO2 and temperature as a result of increased WUE under the elevated CO2. However, the gain would be lower under ETa than that estimated based on ETs due to higher evapotranspiration.
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Yunzhou
authors: Y
authors: Qiao
authors: Shijiazhuang Center for Agricultural Product Quality inspection Shijiazhuang, 050021, China.
authors: Huiling
authors: H
authors: Liu
authors: University of Eastern Finland, School of forest Sciences Joensuu, Yliopistokatu 7, Borealis Building, Box 111, Fin- 80101, Joensuu, Finland.
authors: Seppo
authors: S
authors: Kellomäki
authors: University of Eastern Finland, School of forest Sciences Joensuu, Yliopistokatu 7, Borealis Building, Box 111, Fin- 80101, Joensuu, Finland.
authors: Heli
authors: H
authors: Peltola
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Yueyan
authors: Y
authors: Liu
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Baodi
authors: B
authors: Dong
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Changhai
authors: C
authors: Shi
authors: Library of Shijiazhuang University Shijiazhuang, 050035, China.
authors: Huizhen
authors: H
authors: Zhang
authors: University of Eastern Finland, School of forest Sciences Joensuu, Yliopistokatu 7, Borealis Building, Box 111, Fin- 80101, Joensuu, Finland ; Key Laboratory of Geographic Information Science, Ministry of Education, East China Normal University Shanghai, 200241, China.
authors: Chao
authors: C
authors: Zhang
authors: University of Eastern Finland, School of forest Sciences Joensuu, Yliopistokatu 7, Borealis Building, Box 111, Fin- 80101, Joensuu, Finland.
authors: Jinnan
authors: J
authors: Gong
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Fuyan
authors: F
authors: Si
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Dongxiao
authors: D
authors: Li
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Xin
authors: X
authors: Zheng
authors: Key Laboratory of Agricultural Water Resources & Hebei Key Laboratory of Agricultural Water-Saving, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences 286 Huaizhong Road, Shijiazhuang, 050021, China.
authors: Mengyu
authors: M
authors: Liu
keywords: Aboveground biomass; grain yield; root biomass; soil water depletion; yield components