Research On Air Anion And Landscape Evaluation Of Plant Communities Of Three Sanatoriums In Hangzhou

Plant community is the basic unit of green space, and provides the foundation ecological function of green space. However, few researchers focus on plant communities of sanatorium currently, resorting to data collection and on-site investigation, author surveyed three Sanatoriums in Hangzhou Jiuxi region (the Wuyun Sanatorium, the Shanghai Railway Bureau of Qianjiang Sanatorium, Eastern Airlines Sanatorium), their plant community structures and species diversity, air anion and air quality index, as well as landscape evaluation, hoping to improve the sanatorium industry.All of the 32 plant communities of three sanatoriums, there are 209 species, 154 genus and 83 families of plants, of which 188 species belong to local plants of Zhejiang province, accounting for 89.9% of the total number of plants investigated. 32 plant communities can be divided into the following 5 types: Evergreen and deciduous conifer mixed type holding 13 samples of plant community; Evergreen and deciduous mixed type holding 12 samples of plant community; Evergreen conifer mixed type holding 3 samples of plant community; deciduous broad-leaved type holding 2 samples of plant community; evergreen broad-leaved type holding 2 samples of plant community. Plant community structure, average density of tree layer species was 0.3037 per·m-2, and the average density of shrub species was 0.3846 per·m-2. The average species richness of tree, shrub, grass, and vine in 32 communities was 6.2069, Gleason average index 1.0360, Margalef average index 1.4422, Simpson average index 0.5342, Shannon-Wienner average index 1.1201, Berger-Parker average index 0.4694, Pielou average index 0.3046.From January 2008 to December 2009, the air anion concentration, inhalable particulate, temperature, humidity and wind speed were measured in three Sanatoriums. After analysis, the results showed that the air anion concentration in 32 Sanatorium communities were significantly higher than urban has, and so does the air cleanliness. Air anion concentration is significantly varied from time to time, and it gets peaks from 11:00, also at 17:00. During a year, the air anion concentration changes sequently: summer> autumn> spring> winter; while the air quality rating order is summer> spring> autumn> winter; the NAI order of different structures of plant communities is structure of arbor-bush-grass> structure of arbor-grass> structure of shrub-grass > lawn> contrast; the NAI order of different forest types of plant communities is mixed evergreen and deciduous conifer type> evergreen and deciduous broad-leaved type> evergreen broad-leaved type> evergreen conifer mixed type> deciduous broad-leaved type> contrast; the air anion concentration has negatively correlated with temperature and inhalable particulate (PM10), and it has positive correlation with humidity and wind speed.AHP method is applied to establish a comprehensive evaluation model, from the visual quality, ecological efficiency and health-care functions on a comprehensive evaluation of 32 plant communities. The results showed that: comprehensive evaluation index of community gradeⅠhas 12; gradeⅡhas 15; gradeⅢhas 5; none is the worst gradeⅣ. With the analysis of 9 plantscape: 6 of gradeⅠ, 2 of gradeⅡ, 1 of gradeⅢ, I found that plant communities of comprehensive evaluation index gradeⅠin visual quality, ecological efficiency, health-care function is relatively good; comprehensive evaluation index gradeⅡvisual quality is better, ecological efficiency or health-care function is poor; comprehensive evaluation index gradeⅢhealth-care function, ecological efficiency is better, visual quality is poor.According to the existing problems, three optimization strategies were proposed: to protect and consolidate the plant communities of comprehensive evaluation index gradeⅠ; to adjust and improve the plant communities of comprehensive evaluation index gradeⅡ; to transform and improve the plant communities of comprehensive evaluation index gradeⅢ. Various grades of plant communities on the optimization proposal is to improve self-sustaining and self-renewal of plant communities of gradeⅠ; poor visual quality of plant communities of gradeⅡandⅢshould consider the leaf, flower, fragrance and other factors, use the appropriate health-care plants and aromatic plants; poor ecological efficiency, health-care function of plant communities of gradeⅡandⅢare due to increase amount of coniferous trees and water features. Finally, health-care and ecological construction community and four optimization models were recommended: smell type, hearing type, visual type, touching type.