| In this paper,the soil seed banks,the species composition of the surface vegetation and relationship between the two of the Yeyahu wetland were studied,in which stressed the soil seed banks dring the different periods of water degeneration.A total of 150 Soil samples were collected in 15 seed banks sampling locations being perpendicular to the Guishui River in Yeyahu wetland,in April 2008.All of the sites located were below the water line in the lasted ten years.Surface soil samples were collected and were planted in agreenhouse,subjected to flood,nonflooded and drougt conditions for enumeration of emerging seedlings.Germination experiments continued until there was no germination of new species in August 2008.A total of 78 species was recorded in the seed banks.The density of seedlings emergence was 19456±4916.6 seedlings m-2.There are 36 kinds of tipical wetland plants,subjected to 46.2%in the total plants.We found the most numbers of species,48,during the 5-7-degeneration area.The second was the 3-5- degeneration area,39 kinds of species. The least was the 7-10-degeneration area,34 kinds of species.There are significant differences of the composing of species and the average density of species between different seed banks sampling.Different types of plant have significant different germination number,the largest number of germination were Echinochlos crusgalli, Typha angustifolia,Cyperus glomeratus and Juncellus serotinus.The number of the germinated species in the top 0～5 cm layer,which took 69.6 percentages of all the germinated plant were higher than that of 5～10 cm soil.In May,July and October 2008,a total of 75 1 m×1m vegetation sampling were placed on the primary soil collection sites.A total of 78 species were recorded.The surveys in spring have the maximum number of plant species,followed by the species number in summer and the autumn at least.Dring the different periods of water degeneration,the surveys in the periods of 5-7years have the maximum number of plant species,but the least is the period of below 1 years.The analysis of the vegetation diversity found that the same sampling in the different season and the different sampling sites in same seasons,have different biological diversity index,because of human interference and the changing the climate. We found that the composing of the plant species between the soil seed banks and the surface vegetation were significantly different.The similarity index between the soil seed banks and the surface vegetation was 0.2615±0.0753 in the spring, which was the biggest index,followed by 0.2219±0.0771 in the summer and 0.1841±0.0426 in autumn.Dring the different periods of water degeneration,the similarity index between the soil seed banks and the surface vegetation was 0.2778±0.0539 in the 5-7years and 0.1576±0.0369 in the below 1 year periods.Mainly.Because of the influence of the plant breeding methods,different germination requirements,human disturbance,experimental error and the impact of such factors as the cause,the similarities were relatively low.The purpose of this study was to explore the relationship between the different periods of water degeneration of the soil seed banks and surface vegetation in Yeyahu wetland,and to seek an effective,low-cost,wide ranged techniques and methods of wetland restoration,improve the environment of Yeyahu wetlands,protect the rich diversity of species and maintain the ecological and water quality and safety of the Guanting Reservoir.The experiment proved that there are a lot of vitality types of wetland plant seeds in the soil seeds banks,it is means that wetland soil seed banks play an important role in restoration and reconstruction of damaged wetlands. Through the control of the regional conditions such as the water level and soil conditions,and the using of soil seed banks,the recovery purposes can be achieved.A wetland ecosystem with high richness of vegetation species,nice vegetation landscape, better ecological function and steady ecological structure can be established. |
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