A plateau freshwater lake located in north-western China, Zhaling Lake is the second largest lake in the source area of the Yellow River and serves as a major source of water for communities there. This high altitude tectonic lake is situated within the core area of Sanjiangyuan National Nature Reserve and helps to regulate the hydrology of the region. With its particular natural environment, abundant water resources and productive grasslands, this Site is one of the biodiversity hotspots of the Tibetan plateau biogeographic region. Since 2001, the Chinese Academy of Forestry has led multiple scientific surveys on the Nature Reserve, which have found that this area is among the most species-rich areas in this biogeographic region with about 2,300 plant species, 85 mammals, 238 birds and 40 fishes. Some of these are globally threatened, such as the critically endangered Baer's pochard (Aythya baeri); the endangered steppe eagle (Aquila nipalensis) and Przewalski’s gazelle (Procapra przewalskii); and the vulnerable black-necked crane (Grus nigricollis). The wetland provides stopover and breeding areas for several waterbird species, and it is also an important spawning and nursing site for the fish species endemic to the upper Yellow River, such as Chuanchia labiosa and Gymnocypris eckloni. The Site is also designated as an Important Bird Area.