The Study On Common Landscaping Trees’ Canopy Characteristics In North China

The tree species of North China landscaping are variety and rich. For it planting, only the pursuit ofquantity is not enough. To understand the physiological characteristics of trees can make the best use, Notonly can the trees form a good visual, but in absorbing carbon oxygen, keeping the soil and water tomaximize the advantages of ecological function. With economic development and improved living standards,people’s demanding for the function of landscape is increasingly. It is more urgent and more important toresearch North China common landscaping trees. From46common landscaping trees in North China, thearticle recorded their LAI, DBH, crown width from north to south, crown width from west to east, tree height,crown height, branch number in every periods of one year. Then analyzing the recorded data, the main resultsobtained are as follows:(1)For the common trees in North China, the LAI slowly increase from the beginning of February to theend of March in the first year, LAI to grow rapidly since the beginning of April to end of June, it is the fastestperiod of plant metabolism. There is a slight increase in the month July and August, at this time LAI hasreached the maximum value in one year. Photosynthetic carbon sequestration capacity of plants is also thelargest year-round. LAI declines in early September to mid-October and fast drop down to the lowest in ayear. LAI maintain a minimum value to February of second year, and so forth.(2)Among the parameters in North China landscape tree species, there are high correlation betweencrown width from north to south and crown width from west to east, DBH and crown width from north tosouth,tree height and crown height. The correlation coefficient between tree height and crown height is ashigh as0.819.it is the highest among all the parameters the correlation coefficient. There are neutralcorrelation between DBH and tree height, DBH and crown height, DBH and crown width from west to east,crown height and crown width from west to east, crown height and crown width from north to south, treeheight and crown width from west to east, tree height and crown width from north to south in the samespecies of tree. Other parameters’ correlation is weak or no correlation. For the same parameters on thespecies concerned, several higher correlation species’ linear regression equation are given. It is significancefor plant simulation and predicting growing.(3)The same parameter of different genera take difference test(one-way ANOVA). Assuming there aresignificant differences between the different parameters are the same species, P value were less thansignificant level0.05, So for the same parameters there are significant differences between Different genera.It is concluded that the same parameter of landscaping species in different genera in North China existsfundamental traits distinguish. This is very helpful in guiding effectively plants in cities of North China.