Ex situ and in situ conservation of the rare and endangered species of Davidia involucrata
Davidia involucrata Baill. is a relic deciduous tree species of the Tertiary period with important ecological, scientific and horticultural (ornamental plants) values. It is named Chinese dove tree because its flowers and attendant bracts are pendulous on fairly long stalks, and when stirred by the slightest breeze, they resemble huge doves hovering amongst the trees. It is a beautiful ornamental tree species.
D. involucrata was once widely distributed in China. However, its distribution area has shrunk rapidly due to the changes in the ecological and geological environment, overexploitation and destruction of forest habitat. At present, it can be found scattered in evergreen or mixed evergreen and deciduous forests ranging from 600-2400 m a.s.l in southeast Shanxi, west Hubei, west Hunan, north Guizhou, south Gansu, Sichuan and Yunnan. It's endangered and listed as the Grade I of the National Protection.
Another major reason threatening D. involucrata is that it has a long period of seeds dormancy lasting for 2-3 years even stratified in wet sands, a hard coast of seeds, low germination rate, and low survival rate of seedlings due to damages by wild life. Since 1998, we have carried out studies on its propagation techniques, ecology and conservation. We have made a break-through in germination test, tissue culture and ex vitro culture of D. involucrata and have got 1500 young trees both for 2-year-old and 3-year-old as well as collected 200kg seeds stored in wet-sand so far. It is right time to apply these technical achievements to establish demonstration nurseries and organize training course to make progress in ex situ conservation for D. involucrata.
Successfully implementing this project can maintain the stability of Chinese dove trees in reserves, protect and recover its ecosystem, broaden its quantities and slow down or stop its distinction process by planting Chinese dove young trees in experimental and buffer areas of Xingdoushan and Qizimeishan natural reserves as well as regenerating it artificially. It can also fasten its use in gardens and provide techniques for local farmers who can increase their income by building the sample bases of Chinese dove trees, even further complete the techniques both for seed breeding and tissue cultivation.
|D.involucrata trees||D.involucrata seeds germinating|