Study On The Evaluation Methods Of Plant Communities In Urban Residential Green Area

Urban residential green area as an important component in urban green space systems, it slowdowns the increasing deterioration of urban human settlement environment by means of its peculiarly ecological function. It has become a hot topic on how to perfect its construction and how to evaluate its status with the increasing development potentiality of urban residential green area. In this paper, two evaluation models had been established when evaluation methods based on AHP were appropriately improved. These two models were quantitative AHP evaluation model and comprehensive evaluation model. This study selected three residential areas as experimental objects in Nanjing city. After analyzing the status of plant communities and the index factors, the present status of plant communities were evaluated by applying above-mentioned evaluation models. The main conclusions were as followings:In the plant communities of these three residential green areas, there were 81 species of arbor and shrub plants subordinate to 42 families. The ground cover plants were 44 species belonging to 27 families. The bamboo plants were 6 species. In Wulaocun, ligustrum lucidum obviously predominated in the arbor and shrub plants, the results showed that the plants quantity disposition was unbalanced in this residential area. However, the dispositions were relatively reasonable in Nanlinyicun and Dongfangcheng.The result of quantitative AHP evaluation model demonstrated that the total scores were successively 64.94, 71.64, 71.00 in Wulaocun, Nanlinyicun, Dongfangcheng. The result of comprehensive evaluation model presented that the total scores were in sequence 76.03, 79.57, 79.83. The total evaluation score by the quantitative AHP evaluation model was lower than that by the comprehensive evaluation model from a quantitative view. However, the total scores of these three residential areas were all classified as evaluation grade II with a relatively good quality by either the quantitative AHP evaluation model or the comprehensive evaluation model. Furthermore, the total scores of these three residential areas in both two evaluation models presented the same change trends. This illustrated that the evaluation results of both two evaluation models were basically identical.The evaluation results were consistent with the status of plants communities in these three residential green areas. These two models showed fairly good evaluation effects in practical application. There were merely five index factors in quantitative AHP evaluation model, this model provided stronger operability in a macro-scale view for the diversity index of plant communities. Therefore, the quantitative AHP evaluation model was more suitable for evaluating all the plant communities in the entire residential green area. There were more index factors in the comprehensive evaluation model, this model comprehensively reflected the status of plant communities in detail. Consequently, the comprehensive evaluation model was more suitable for evaluating the single plant community, especially in four green space types of urban residential area.