The Analysis Of Plant Community Structure And Plant Diversity Of Tianjin Port

With the rapid economic development and urban residents in the material life level unceasing enhancement,Requirement of people to the urban ecosystem is higher and higher, how to construct a reasonable and steady urban ecosystem has received more and more attentions.Plant community is the foundation of urban ecosystem, is the basic unit of urban green space.In order to understand the status and role of plant community and plant diversity and its effect on sustainable development in urban ecosystem building of port city.This paper investigates the landscape greening plant community of Tianjin Port.The main results are showed as follows:1 There are 98 plant species in study area, which are respectively belonging to 63 categories of 37 families. Among them, there are 19 species belonging to Rosaceae and 10 species belonging to Leguminosae,deciduous plant species is used widely in the green space of Tianjin Port.2 The spatial structure of community of Tianjin port is divided into horizontal s patial structure and vertical spatial structure. Horizontal spatial structure in the mix ed community is dominant with relatively larger share is 84.21%, pure forest comm unities accounted for a smaller proportion of 15.79%.Vertical spatial structure can b e divided into 6 types,trees +(shrub +shrubby hedge) + ratoon flowers+ grass accounting to 52.76%,trees + shrub + ratoon flowers + grass accounting to 28.14%,trees +(shrub +shrubby hedge) + grass accounting to 9.05%, trees +grass accou nting to 5.03%, trees + shrub + grass accounting to 4.02%, and trees + ratoon flo wers + grass accounting to 1.01%.3 Trees in the green space of Tianjin Port,the lagest average DBH class is Salix babylonica 25.00 cm, while the smallest is Pinus tabuleaformis is 3.61 cm, average DBH classes distribute interval 10.00cm~12.00 cm and the number of trees is most. The biggest average tree height is Populus tomentosa 11.46 m, while the smallest is Sabina chinensis 4.13 m, average tree height distribute interval 5cm~10cm and the number of trees is most. The biggest average health condition is Koelreuteria paniculata 3.96, while the smallest is Ginkgo biloba 2.67, average health condition distribute interval 3.00—3.80 and the number of trees is most.4 The highest frequency of emergence are Sophora japonica and Populus tomentosa in the green apace of Tianjin Port.Sophora japonica emergence in 76 sample ares of the slected 197 and Populus tomentosa emergence in 64 sample ares. The lower frequency of emergence are Salix babylonica, Prunus davidiana, appering in 2 of the sample ares, while Acer truncatum, Sophora japonica ‘Pendula’ only appering in 1 of the sample areas.5 The important value of plant community in the green space of Tianjin Port. Populus tomentosa and Sophora japonica is far better than the other tree species, accounting for 20.74%and 16.19%, while Sabina chinensis‘kaizuka’,Robinia hisqida‘Decaisneana’,Salix babylonica are small,all less than 1%. Euonymus japonicus,Ligustrum ×vicaryi, Sabina chinensis‘kaizuka’,Amorpha fruticosa is far better than the other tree species, accounting for 8.12%、15.44%、14.05%and 13.22%,while Prunus persica ‘Bai Bitao’, Malus ’Kelesy’, Jasminum nudiflorum, Buxus bodinieri are small, all less than 1%.6 Pecies diversity index of plant community of forestbelts in Tianjin Port is low. The community’s species richness index, species diversity index and equality index reflect accordant trend. The diversity index of tree layer and shrub layer of the third area garden is highest among the plant communities,the diversity index of grass layer of Tianjin International Cruise Home port is the highest level. There is great difference in differente plant community of Tianjin Port of species diversity, among the three layers, tree layer >shrub layer> Herb laye, biodiversity index display positive connection in diffenert layers.