The Study Of Community Structure And Ecological Function Of Urban-circulating Forestbelts In Baoding City

In order to understand the characteristics of structure,characteristics of species diversity,characteristics of ecological function of urban-circulating forestbelts in baoding city,An assessment was proposed reasonably through investigating the present situation of urban-circulating forestbelts in baoding city.For planning,designing,and managing urban-circulating forestbelts in baoding city.Some important indices about that the floristic composition,the important value of plant community,the hierarchical cluster dendrogram,species composition,DBH classes,health condition and LAI of the tree community were analyzed as well as it were conducted by diversity comparison.The main results are showed as follows:1 There are 47 plant species in study area,which are respectively belonging to 44 categories of 27 families.Among them,there are 5 species belonging to Rosaceae and 5 species belonging to Compositae and 4 species belonging to Leguminosae,temperate predominate native tree species is used widely in urban-circulating forestbelts in baoding city.2 There is 49% plant community only have tree layer.In addition,single tree species composition account for 31% of tree layer.The greening tree species are the common landscaping tree species.There are tree species ordinary,North original species of China which were Populus tomentosa,Salix babylonica and Amorpha fruticosa higher than other tree spices,and its function of urban ecology environmental protection,beautification of that trees is small.3 Tree structural index of each loop road are still at lower level.Overall,Tree layer of north thirds circle and west thirds circle better than other circle road,structural index of north second circle is low because younger age of tree.4 DBH of is 10.39cm of urban-circulating forestbelts in baoding city,There is 58.66% of trees distributed interval 8cm~16cm and the number of trees is most.Average tree height is 8.40m,there is 58.20% trees is higher than the average level.Average tree height and DBH of tree was relatively small.That have sufficient potential grew upward and forward.5 Interaction obviously and almost show strong relationship with tree density and other tree structural index.Four factors contain 82.1% of information content:tree height,average DBH,crown diameter of tree,canopy height of tree.6 Pecies diversity index of plant community of urban-circulating forestbelts in baoding city is low,The community's species richness index,species diversity index and equality index reflect accordant trend.Pecies diversity index of tree layer trend.order is as follows:north second circle>north thirds circle>south second circle>west third circle>east second circle,shrub layer is north thirds circle>south second circle> west third circle>north second circle>east second circle,herb layer is north thirds circle>south second circle>west third circle>east second circle>north second circle.there is great difference in differente urban-circulating forestbelts in baoding city of species diversity, among the three layers,the Sharmon-Wiener index,Simpson index and Pielou index in the herbs layer are the heighest,and the tree stratum are the lowest. biodiversity index display positive connection in diffenert layers.7 the ecological function order is as follows:south second circle>north thirds circle>north second circle>west thirds circle>north second circle>east second circle,the more canopy density and more width of greenbelt is more beneficial to warming,dyhumidification,noise reduction,wind prevention,detaining dust and so on,but bacteriostatic ability is decreased.ecological function of differently structured order is as follows tree+shrubs+herbs>tree+shrubs>tree+herbs>shrubs+herbs.Differernt community type has different ecological fuction.Faction of ecological function order is as follows Catalpa ovata>Populus tomentosa>Salix babylonica>Sabina japonica var pubescens community.8 Some suggestions about different plant type arrangement,the selection of trees,species diversity,improve plant community structure of urban-circulating forestbelts in baoding city were put forward.