Tao Lyu1,2, Shubiao Wu3, Robert J G Mortimer1,2, Gang Pan1,2,4. 1. School of Animal, Rural and Environmental Sciences , Nottingham Trent University, Brackenhurst Campus , Nottinghamshire NG25 0QF , United Kingdom. 2. Centre of Integrated Water-Energy-Food studies (iWEF) , Nottingham Trent University , Nottinghamshire NG25 0QF , United Kingdom. 3. Aarhus Institute of Advanced Studies , Aarhus University , Høegh-Guldbergs Gade 6B , DK-8000 Aarhus C , Denmark. 4. Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , 18 Shuangqing Road , Beijing 100085 , China.