BEIJING: 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.
However, villager Zhang came up with a method of pollination. When the plant was blossoming, he cut off a branch from one tree and tied it to another so that pollen from one tree can travel to another easily. He succeeded and got over 2,000 seeds, which he sent to Sun Weibang, head of the Kunming Botanical Garden in 2008.
After receiving the seeds, Sun’s team used special technology to cultivate 1,600 seedlings. Some of the seedlings were planted at the Kunming Botanical Garden and some were sent back to Zhang to be planted in their original habitat.
Through genetic analysis, researchers found that the seeds from Zhang all came from the same plant but the pollens were not only from the trees that had been found but from other trees. They therefore drew the conclusion that there were trees that hadn’t yet been discovered. Sun’s student Tao Lidan carried out a systematic investigation and found that there were 577 trees distributed in 12 locations.
In 2016, researchers cultivated more seeds and in 2017 they had 50,000 seedlings, 50 of which were grown at the Kunming Botanical Garden, 4,600 were grown in their original habitat and 8,000 were grown in forest farms in Yunnan’s Yunlong County and Honghe Hani and Yi Autonomous Prefecture.
There are still 38,000 seedlings at a nursery waiting to return to nature. Now the first batch of seedlings planted at the Kunming Botanical Garden in 2009 have grown up and can blossom and produce seeds. Sun says the species is now out of danger.
– The Daily Mail-Beijing Review News exchange item
