| Appearance of city is human of moving towards ripeness and civilized sign, it also is the high form of human colony formation. It is a concentration of popularity, industry and technology. Urbanization is the trend of the development of human society. Cities grew rapidly, population increase quickly and environmental have deteriorated sharply, atmospheric pollution, water pollution, noise pollution, urban heat-island effect and emissions increased threaten seriously life and health of citizens. Forest is becoming an important means of improve the ecology environment with its nitrogen fixation and oxygen release, dust prevent, absorb harmful gases, adjust the temperature, reduce the noise and so on. Urban forest has been borned. As urban forest theory develops, so will the estimate index. As a new green standards of evaluation of urban forest ecological environmental benefits, the role of tridimensional green biomass is increasingly attracted people's attention. Tridimensional green biomass reflects the spatial structure of urban forest relative to plane biomass. Stratified structure greenbelt constructed by combination of arbor, shrub and grass. Their ecological benefits significantly greater than double or single structure. Tridimensional green biomass is a new urban eco-environment benefit index, reasonable planning of green quantity to fill the requirements of daily life of the city people and keep a good urban eco-environment is the urban forest establishment focus.This paper use the new natural color aerial photo of Harbin and the data collected in field by Nangang forestry bureau in the same period. This paper seted up the uniform grid spaced at 50* 50 on the natural color aerial photo and calculate the TGB in a grid cell used amended Logistic model to bulid equation of "crown diameter-height", matched the corresponding Stereoscopic geometry model. And the total TGB in Harbin has been calculated.Obtain the main impact factors are the average crown height, average crown diameter and sample density, and return the best equation used the stepwise regression method to discuss the possible confoundings of TGB include average tree height, average diameter, average canopy density, average crown height, average crown diameter, sample density, average basal area and TGB per unit area. The vertical distribution of height, crown height and TGB of urban trees in the Harbin was studies by means of gathering the TGB of trees in the center point of tree canopy. Results show that the vertical distribution of height and crown height fit the left distribution, and the vertical distribution of TGB close to a normal distribution. The TGB will depend ever more on vertical structure while young forests'contribution are lesser. This paper divided Harbin into 5 types include public facilities area, living area, industrial area, road area and external transport area are, based on different types need differnent functions of the TGB, evaluate urban forest ecological environmental benefits by take a method using AHP to calculate the weight of tridimensional green biomass which supply to each type and contrast existing tridimensional green biomass.
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