Primary Studies On Plants And Vegetation In Han Shiqiao Wetland Nature Reserve In Beijing

The wetland vegetations in Han Shiqiao wetland nature reserve in Beijing were analyzed respectively and thoroughly, including diversity of wetland vascular plants, the interspecific relations of plant communities, and the relations between plant communities and environments. And then several stratigies for wetland protection and restoration were proposed based on our results.One hundred and eight sample plots were set totally. Transect lines were perpendicular to separation line between water and land, and composed of 4～6 square sample plots whose distance was1～2m. There were 1～2 square plots of aquatic plant and 3～5 square plots of terricolous plant in each transect line.The area of herby squares was 1 m~2, the depth of water, the names of species, the individual amount, the average height, and the coverage were recorded.Totally 129 vascular plant species (variation) were recorded, belonging to 89 genera and 39 families, including Ferns (1 specie, 1 genus, 1 family), Dicotyledon(90 species, 63 genera, 28 families), Monocotyledon (38 species, 25 genera, 8 families). The cosmopolitan type, tropical type and emperate type were dominant in genera of wetland vascular plant. The cosmopolitan type, pantropical type and the north temperate type were dominant in genera of wetland vascular plant. The wetland species were abundant in kind, but it is lack of peculiar genera and families.The diversity status of wetland vascular plant in Beijing was evaluated by comparing the values of species richness index, species diversity index and evenness index with other wetland nature reserves in Beijing. The results indicated that the richness of species in Han Shi-qiao is higher, whereas a lower diversity index value was caused by the destructions done by human beings and the singleness of the introduced species. Meanwhile, the distribution of the artificial plants species was so centralized that it made the evenness index value the least among the Wetland Nature Reserves in Beijing.The interspecific relations of 19 dominant species were studied by using X~2 -test, Jaccard's association index and Spearman's rank correlation. The results showed that a majority of the species-pairs had negative association, and minority revealed significant and very significant correlation; the 19 dominant species were classified into 3 ecological groups: hydrophytes ecological group, hygrophytes ecological group and mesophytes ecological group. Species in an ecological group had similar ecological requirements and resource-using ways, and species in different ecological groups showed inapparent correlations.TWINSPAN and DCA were combined to classify and collate one hundred and eight quadrats of the wetland vegetations into 19 associations. The first axis in the ordination by DCA expressed the gradient of soil moisture while its second axis depicted the changes of soil types. The proportion of hygrophytes associations is lower. The mesophyte associations and xerophyte associations were in quantities because of scarcity of water resources, human disturbance and water pollution. The results indicated that soil moisture and types play a dominate role in plants distribution in Han Shiqiao wetland nature reserve.On the base of analysis to the reasons of wetland degradation, several countermeasures of restoration and protection were suggested in this paper.