In May 2018, the resource survey of ancient and precious trees has been launched in 54 counties of 6 cities (prefecture) in southwest China's Tibet Autonomous Region, including Lhasa City, Nyingchi City, Shannan City, Xigaze City, Qamdo City, as well as Ngari prefecture.

According to the statistics, more than 38,652 ancient trees have been discovered, among them, there are 4,590 first-grade trees, 15,400 second-grade trees and 18,600 third-grade trees. Besides, 14 ancient tree clusters including 2 in Lhasa, 1 in Xigaze, 2 in Shannan, 5 in Nyingchi, 2 in Qamdo and 2 in Ngari have been discovered. Numbers of ancient trees in these clusters range from 30 to 3,000. Big Cypress of Bayi District in Nyingchi, with the age of 3,200 years, has been rated as the oldest tree in Tibet.