1. College of Water Conservancy and Civil Engineering; Inner Mongolia Agricultural University; Hohhot 010018 China
2. Institute of Grassland Research of the China Academy of Agricultural Sciences; Hohhot 010010 China
3. LEAF-Research Center on Landscape, Environment, Agriculture, and Food, Institute of Agronomy; University of Lisbon; Tapada da Ajuda 1349-017 Lisbon Portugal