Study On Stand Density And Adjacent Interference Of Cinnamomum Camphora And Ligustrum Lucidum In Shanghai

Urban Park and Out-ring Greenbelt are the important component of urban green space system in Shanghai. Cinnamomum camphora and Ligustrum lucidum, as one of the most common and useful species, not only own the higher frequencies but also play an irreplaceable role in improving the urban elecological environment and enriching the urban landscape. Ten parks in urban green spaces, five plots of the whole Out-ring Greenbelt and three suburban greenland make up of the investigation sites.The main task of this paper are to analyze stand density,neighborhood interference, light habitat,soil hablit and the relations between them of these two specices, aim to clarify the present situation of stand density,and then establish stand density table of Cinnamomum camphora and Ligustrum lucidum, to analyze the difference in different stand density gradient, to draw consice location diagram among neiborhood plant, to investigate the relationship among light,canopy gap and under stand regeneration, to research the change of stand density with different soil habitat. This can supply strong theoretical support for management and protection for landscape departments.1. Density analysis of Cinnamomum camphora and Ligustrum lucidum communitiesStand density is a key factor which can restrict the normal growth of threes, and also play premise and bledding role in the formation of reseanable commity structure and ecological fuctions. Density of Cinnamomum camphora stand distributes from 175 trees/hm2 to 2800 trees/hm2, and we change it into six grades in order to compare and regression analysis. The results of investigated areas show that relationship between density and DBH, density and CWof Cinnamomum camphora are y= 4433.8x-0.614 (R2=0.9731)and y= 220.73x-0.5395(R2= 0.9539); Density of Ligustrum lucidum stand distributes from 400 trees/hm2 to 3650 trees/hm2, and we change it into six grades in order to better compare and regression analysis. The results of investigated areas show that relationship between density and DBH, density and CWof Ligustrum lucidum are y=-9E-06x2+0.0232x+32.865(R2=1)and y= 2305.7x-0.7761(R2=0.7869). Along with the greater density,hight of the lowest branch of the both species are higher.2. Establish stand density diagram of Cinnamomum camphora and Ligustrum lucidumIt is significant positive linear relationship between DBH and CW of the plant. Statistical proceed every class size and their corresponding average DBH and CW of the investigated areas, and make full use of the relationship equation to calculate theoretical value of the CW. According to the relationship among CW, crown density and crown umbriferous area, establish stand diagram.3.Neighborhood interference analysis of Cinnamomum camphora and Ligustrum lucidum communitiesThe negative process and affect that made by Neighboring plant compete available resources named neighborhood interference, and it is closely related with the space between plant and the influnces degree for available resources.According to the excessive density question, especially in the out-ring greenbelt, we survey all the neiborhood factors such as spaces, DBH, CW and so on to calculate the interference index and draw the position map. Choose 24 tipical samples, including 12 urban greenland samples and 12 suburban greenland samples, use the original data to calculate index, such as Iw, Ix, Iij, APA and so on, with the purpose of analyzing neiborhood effct of different communities.4.Biological analysis of shrub and herb layer in Cinnamomum camphora and Ligustrum lucidum communitiesSpecies richness index, shannon-Wiener index and simpson index of both Urban greenland and Suburban greenland show consistent tendency:shrub layer>herb layer. About species richness index, New Jiangwan Ecological Corrider is the highest of all the urban communities while Jiading Area is the highest of all the out-ring communities; About shannon-Wiener index and simpson index, New Hongqiao Garden is the highest of urban communities while Sanlin Area is the highest of the out-ring communities; About species Pielou evenness index, out-ring communities is more higer than urban ones, especially obvious of the herb layer.this is because there is not many people who come and go frenqutly in out-ring area,and the human interference is relatively small.5. Analysis of the relationship between stand density and habitat factors Measuring the value of light intensity in and out of forest using the light meter,estimating the crown density and calculating porosity of the canopy, we look into the relationship between the amount of regenerated plant and light factor. Through LAI2000 machine, LAI value can be got to research how it related with the porosity of the canopy. And the results shows that they make form of the Power Fuction, which is y=1.0874e-0.5833x(R2=0.7537),y= 0.7563e-0.619x(R2=0.8024)。The average pH of investigated area mostly distributes from 7.5 to 8.5,which accouts 78%, and this shows that the soil is in alkalescent.By comparison urban greenland is better than suburban greenland in some physical properyies of soil, such as moisture content, soil bulk density, pH and so on.