1.1 Study area
Yunnan province is located between 21° 8’ 32”~29° 15’ 8” N and 97° 31’ 39”~106° 11’ 47” E, with a total area of 394,100 km2 and spans an altitude of 76-6740 m. This area is characterized by sharp altitudinal gradient and the six large rivers – Mekong (澜沧江, Lancang Jiang), Irrawaddy (独龙江, Dulong Jiang), Salween (怒江, Nu Jiang), Red River (红河, Hong He), Pearl River (珠江, Zhu Jiang) and Yangtze River (金沙江, Jinsha Jiang) cutting across the province. This complex topography helped shape the region’s relatively closed ecological zones, where biodiversity is extremely high.