[1] Chinese Acad Sci, Inst Tibetan Plateau Res, Lab Alpine Ecol & Biodivers, Beijing 100101, Peoples R China
[2] Peking Univ, Coll Urban & Environm Sci, Dept Ecol, Beijing 100871, Peoples R China
[3] Princeton Univ, Dept Ecol & Evolutionary Biol, Princeton, NJ 08544 USA