Tibetannet

Photo taken on May 7, 2020 shows blue sheep at Mount Qomolangma National Nature Reserve in southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Jigme Dorje)

Photo taken on May 13, 2020 shows a seabuckthorn tree growing at the foot of Mount Qomolangma, in southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Purbu Zhaxi)

Aerial photo taken on May 16, 2020 shows a seabuckthorn forest growing at the foot of Mount Qomolangma in southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Jigme Dorje)

Photo taken on May 13, 2020 shows a flock of sheep in Pasum Village at the foot of Mount Qomolangma, in southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Sun Fei)

Photo taken on April 29, 2020 shows a yellow-billed chough at Mount Qomolangma National Nature Reserve in southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Jigme Dorje)

Photo taken on May 4, 2020 shows the wetland in Pasum Village at the foot of Mount Qomolangma, southwest China's Tibet Autonomous Region. Mount Qomolangma National Nature Reserve was set up in 1988. Covering an area of more than 33,800 square km, it is home to one of the world's most vulnerable ecosystems. (Xinhua/Purbu Zhaxi)