1. Institute of Ecological and Environmental Science, College of Environmental Science, Sichuan Agricultural University, Chengdu 611130, People’s Republic of China.
2. Key Laboratory of Crop Ecophysiology and Farming System in Southwest China, Sichuan Agricultural University, Chengdu 611130, People’s Republic of China.
3. College of Landscape Architecture, Sichuan Agricultural University, Chengdu 611130, People’s Republic of China.