Reproductive Ecological Research On Endangered Plant,Kingdonia Uniflora Populations

In this thesis, research on Kingdonia uniflora populations was carried out by using theories and methods of population statistics and reproductive biology, we drew these conclusions:1. They are isolated in high mountain of Qinling and Southwest in China. They require special habitat and wet and cool habitat is suitable for their living. Their distributing areas in China are: Doker-la of Yunnan, Northwest Sichuan-South Gansu, Taibaishan mountains and the surroundings of Shaanxi. In Shaanxi, the main distributing areas are Pingan temple,Mingxin temple etc.They like shady and cool,fertile,damp, with abundant humus ,acidic dark brown forest soil, only live in the communities of Larix chinensis, Abies fargesii, Rhododendron clementinae subsp. aureodorsale, Betula utilis and Sinarundinaria nitida. So destroying habitat that they live on is important reason for their endangerment.2. The main expanding way of Kingdonia uniflora population is lengthening of their rhizomes. Their clonal architecture is "guerilla". The models of "foraging behavior" can be classified three types: single direction, two directions and many directions. The new ramets can be reproduced from either the terminal buds or the lateral buds. Reproducing new individual is mostly occurred from more than 3-year old rhizome. The reproductive ratio of Kingdonia uniflora population is 1.05 in 2000 and 1.35 in 2001, which can maintain stabilization of local population for period of time. 3. They can blossom and fruit, but seed can not germinate. There are obstacles in their sexual reproduction. They are flowering earlier than spreading leaf plant. In Taibai mountain, blossoming in the first ten days of May, fruiting in the last ten days of June and dropping fruit in the last ten days of August .The germination ratio of their pollen is low, 4.01% at the mean level. In different communities, from maximums to minimums is: Rhododendron clementinae subsp. aureodorsale＞Larix chinensis＞ Betula utilis＞Abies fargesii. The blossoming and seeding percent is obviously different in different communities. Among the four communities, the two percent of Rhododendron clementinae subsp. aureodorsale is the largest, the blossoming percent of Abies fargesii is smallest, the seeding percent of Betula utilis is the smallest and the two percent of Larix chinensis are between them. In the biomass allocation of population in different communities, the percent of rhizome is the largest, but the percent of flower or fruit is the smallest. The factors, which affect biomass allocation much are temperature and moisture of soil.4. The main reasons for their endangerment are: (1) The process of sexual reproduction having obstacles and their asexual reproduction ways restricted their expanding.(2) They are habitat-relying species, and limited habitat also restricted their expanding.(3)Their isolated distribution reduced the diversity of genes and fitness to habitat. 5. Taking their endangered reasons and biological and ecological characters into account, we put forward some protecting measures: (1) Protecting habitats where they grow, such as Larix chinensis ,Abies fargesii, Rhododendron clementinae subsp. aureodorsale, Betula utilis and Sinarundinaria nitida. (2) Transplanting them in some suitable habitat to carry out ex situ conservation. In the meantime, exploring means of sexual reproduction, introduing populations of Sichuan and Yunnan into Qinling in order to promote cross of populations from different region. (3) Increasing research expense and making comprehensive research on their endangered reasons and mechanisms.