By Ji Jing

Acer yangbiense， a critically endangered maple tree unique to Yangbi County in Yunnan Province， has grown from four when it was first discovered in 2002 to tens of thousands through years of conservation efforts.

In recent years， Yunnan， nicknamed the“kingdom of plants and animals” for its rich biodiversity， has carried out over 120 conservation programs to rescue more than 100 endangered species including the Asian elephant and the Yunnan snub-nosed monkey. These programs have increased the number of Asian elephants from 193 to 300 and the Yunnan snub-nosed monkeys from over 1，000 to over 3，300.

One might ask whether it is worthwhile to exert so much effort on protecting such rare species. The answer is yes because scientists have found that the extinction of one plant species may lead to the extinction of 10 to 30 other species in future because every animal and plant species and every microorganism is crucial to maintaining biodiversity.

Interesting discoveries

In 2001， Chen Yousheng， a doctoral candidate with the Institute of Botany， the Chinese Academy of Sciences found a sample of a maple tree from Shizhong， a village in Yangbi. He noticed that the tree was different from other maple trees and concluded that it might belong to a new species. He went to the village to look for the trees and found four of them in 2002. As the tree was unique to Yangbi， Chen named it after the county.

In 2007， Chen started to carry out protection of the plant with funding from the Botanic Gardens Conservation International （BGCI）， an organization that engages botanic gardens and other partners in securing plant diversity.

In addition to educating local people to improve their awareness of protection， he has also conducted artificial breeding in the hope of getting more seeds.

Villager Zhang Guoshu， responsible for protecting the trees， visited them regularly and persuaded other villagers to protect them. His duties also included stopping animals from eating the trees and preventing them from being stolen.

Zhang said in the beginning some villagers wanted to steal the trees because they thought they might be valuable since the plant had attracted so much scientific attention. However， after finding that the trees had neither ornamental nor medicinal value， they soon lost interest.

How to bring the plant back from the brink of extinction？

Sun said the species became endangered not only because its biotope—the region of a habitat associated with a particular ecological community—had been destroyed by human activity but also because the tree has a very short flowering season， reducing the chance of pollination. Moreover， with so few trees left and scattered far from each other， pollination became even more difficult.