Assessment On Landscape Quality Of Urban Forest In Residential Area In Beijing

150 plots of in-forest landscapes within 14 residential communities in Beijing were investigated in order to explore the influent mechanism of in-forest landscape quality of residential community. The study was to learn the structural characteristic of landscape forests by measuring the plant species, individual size, spatial structure and aesthetic structure. It analyzed the mechanism of in-forest landscape quality by the relationship between in-forest landscape indexes and scenic beauty estimation. An evaluation model for in-forest scenic beauty values was constructed on basis of 17 indicators such as average diameter at breast height and coverage of undergrowth shrubs. The main findings are as follows.(1) At present, the majority of the landscape forests arc the trees in small diameter. The whole forest is in a rapid growth period and the increment protential value of green space is 2.06. The public opinion survey result showed that the public loved the rich plant species and high proportion of big trees. The main factor to reduce the public satisfaction is unreasonable selection of tree spieces and monotonous color of trees.(2) The results showed that the quality of landscape forest with average diameter, coverage of undergrowth, stand vercal stratum and other nine indicators have a significant correlation by correlation analysis. The quality of in-forest landscape in residential area mainly depended on the individual size index, the color index and other characteristic indices of in-forest landscape. Distinguishable outline of tree canopy and trunk, regular forest appearance, strong forest color contrast, high proportion in multi-seasonal change tree species and high degree of forest naturalization were benefit to improving the quality of in-forest landscape.(3) The quadratic polynomial model (R=0.83) was constructed in which the in-forest landscape characteristic indexes were independent variables and scienc beauty values of in-forest landscapes were dependent values. It established the in-stand quality graeds for landscape forest by different value of landscape characteristics among five quality levels.(4) Choosing tree species with colorful and multi-seasonal change characteristics by modulating spatial configuration, increasing closc-to-nature degree of landscape forest by modulating stoc density and tree species component were key techniques for establishing high quality landscape forest scientifically in residential areas.