Study On Green Volume And Eco-efficiency Of Landscape Plants Of Dongshan Street In Jiangning District Of Nanjing

With the rapid development of urbanization,the increasing of urban population and urban building density,the city is facing many problems,such as the heat island effect,the poor ecological stability and so on.Urban green space is an important way to solve these problems.In the extremely tense urban area,constructing landscape not only need to consider the landscape effect,but also take the ecological benefits into account,to improve the ecological effect of green space per unit area.In this paper,taking the green quantity as the main line,carbon sequestration,oxygen-releasing,cooling and humidifying as the ecological benefit index,to study the green quantity and ecological benefit of Dongshan street in Jiangning District of Nanjing city.According to the preliminary investigation,46 samples were selected,which were divided into four types:park greenland,attached greenland,residential greenland and road greenland.Analyse the relationship of green quantity and ecological benefits,and growth parameters of single plant(DBH,tree height,crown width)and community(green rate,plant density and canopy density),to provide scientific basis for scientific construction the green garden city.The results are as follows:(1)Select the most common landscape tree species in the 46 plots of the study:Camphor,Cherry Blossom,Ginkgo,Halliana and Albiziajulibrissin.According to the measured data,the regression equation of DBH,tree height and green quantity was established.Green area per unit size:Cinnamomum camphora>Albizia julibrissin>Ginkgo>Halliana>Cherry Blossom.On the whole,with the increase of tree's height and DBH,tree crown area increased,the green quantity increased.Camphor and Cherry Blossom's regression equation of DBH,tree height and green quantity was higher,and the relationship was significant among the five tree species.(2)The statistics of four kinds of green space plant community index(species,number,tree height,DBH,tree density),found in Dongshan street Jiangning District Community Tree DBH mainly concentrated in the 10-30cm range,the average DBH of trees in the road green space,other types of difference;high<8m tree the scope,mainly distributed in less than 6m;the average DBH of the campus green,road greenbelt,minimum average DBH;plant density of plant communities mainly concentrated in<1000 plants/ha-1000 plants/ha,plant density of road green space relative to that high.(3)A total of 46 samples of green quantity and unit green is calculated and found four kinds of green green green communities were relatively small,<4000m2,kind of green value concentrated in the range of 2000 m2,indicating that 2000m2 is more reasonable within the scope of the four types of green green quantity.The green area per unit area of each type of plot was more consistent,and it was concentrated in the range of 10000-50000m2/hectares.(4)The ecological benefits(carbon fixation,oxygen release,cooling and humidification)values were calculated on the basis of green quantity.The total amount of carbon fixation,total oxygen release,and the total amount of cooling were the highest,and the carbon fixation,oxygen release and cooling capacity were the highest in the unit area of road green space.On the whole,the ecological benefit of unit area is the best.