Research On Plant Species Metapopulation And β Diversity In Middle And Small Area Islands Of One Thousand-island Lake Region

With development of industrialization and urbanization, disturbance of human activity on ecosystem is increasing. Habitat loss and fragmentation become more and more serious. Habitat fragmentation is one of key factors for decrease of biodiversity, so people focus more and more on protection of species in the fragmented habitat. Island biogeography theory, minimum viable population theory and metapopulation theory are three key basic theories on conservation biology. In this thesis, firstly, we review three theories, the relationship between island biogeography theory and metapopulation theory, and development processes from classical metapopulation theory to modern metapopulation theory briefly. Secondly, we focused on key topics of metapopulation theory:spatial dynamics, and recent research advances of metapopulation at national and international lever. Thirdly, there were many different views from different scholars on metapopulation, for example different views and opinions on phenomenon of extinction debts. Large area is very important in protection of species, yet connectivity and heterogeneity can't be neglected, they also are important factors for species conservation.When we can't build large reserves in a short time, the study on metapopulation is helpful for guiding of protection approaches, and improving work quality of biodiversity conservation. Also extensive research of metapopulation is conducive to increase biodiversity conservation and ecosystem health. One-thousand Island Lake was formed by Xinanjiang Reservoir construction in 1959 that resulted in the fragmentation of the original habitat, and appeared thousands of islands. These islands are a nature laboratory for experiments on metapopulation and metacommunity. We selected 10 typical small islands in the centre of lake in our study, investigated plant species of each island, and calculated (3 diversity among islands. Then we did an analysis of relationships among distance (among islands) and corresponding value ofβdiversity.The results showed that:(1) distance had a remarkable effect on the distribution of species. The value ofβdiversity was lower when the distance among islands was closer, indicating high species similarity; (2) we also found area effects by analyzingβdiversity values on larger islands. For the larger islands, theirβdiversity values increased along with the area decreasing of corresponding islands. We also found that P diversity values of plant species had no fixed rule when the larger islands mating smaller islands, and also reasons for this phenomenon were analyzed in the text.We also found that island area not only effect species diversity, also has an effect on the metacommunity. Dominant species on the large islands were different from that on the small islands. As islands are close to each other and not separated for adequate a long time, the fruit shape indexes of Ophiopogon japonicas and Quercus fabri revealed no significant differences between islands.