Study On The Plant Landscape Evaluation And Design Of Tianjin City Parks Under The Resource-Saving Guidance

The paper focused on the typical plant communities in Tianjin City Parks and the plant communities investigated were divided into water-saving,material-saving and land-saving communities according to the unit of the parks.The Analytic Hierarchy Process(AHP)was used to construct the comprehensive evaluation system of the water-saving,material-saving and land-saving plant landscape in city parks and to evaluate the corresponding communities.Then,the evaluation result was analyzed in detail.On this basis,the plant materials suitable for the climate of Tianjin were screened out to create different resource-conserving plant landscapes,and the community models and optimum designs were proposed.Main contents and results in this paper were as follows:(1)Investigation and research on plant communities in Tianjin City ParksThe investigation focused on greenbelt in the area of Tianjin city parks and 7 parks with different age,different area,different function and different scale were elected.In these parks,a total of 30 typical plant communities which included complex type,sparse forest type,forest type,waterfront,mountain shape were studied.They can basically reflect the plant landscape overview in Tianjin city parks.According to the survey results,there were a total of 140 species of seed plants which belong to 47 families and 101 genera,and 57% was the native tree species,in which deciduous broad-leaved trees were dominant.In distribution pattern,the family of cosmopolitan and north temperate had obvious advantage.The plant community mainly contained the needle broad-leaf type,the defoliation broad-leaf type and the evergreen-defoliation broad-leaf type,in which the needle broad-leaf type was the most.The vertical structure of the communities was based on the arbor-shrub-grass type and its spatial pattern was half open space and covering space.(2)Evaluation of the plant communities in Tianjin city parksIn this paper,the research object was first classified into the water-saving landscape,the material-saving landscape and the land-saving landscape due to the characteristics of water-saving plant,material-saving plant and land-saving plant landscape.The water-saving landscape in city parks included Munan Park,People’s Park and Bridge Garden,the material-saving landscape contained Shuishang Park and Taifeng Park,and the land-saving landscape included Hedong Park and Nancuiping Park.And then,landscape evaluation systemwas established on the city park plant of the water-saving type,the material-saving type and the land-saving type.Each system consisted of 12 evaluation factors.Depending on the expert rating and evaluation,the weights ranking of the criteria layer was: Ecological ? Ornamental > Cultural Degree;the weights ranking of water-saving type factor layer was: Adaptability = Drought tolerance = Planting structure > Nativity >Plane composition = Spatial composition = Seasonal change = Environmental harmony > Species diversity > Implied meaning = Interactive experience > Health care.The weights ranking of material-saving type factor layer was:Adaptability = Maintenance requirement > Nativity > Species diversity > Economic value >Plane composition = Spatial composition = Seasonal change = Environmental harmony >Implied meaning = Interactive experience > Health care.The weights ranking of land-saving type factor layer was: Adaptability = Cropping pattern > Nativity > Species diversity = Vertical planting = Seasonal change = Environmental harmony = Spatial composition = Plane composition > Implied meaning = Interactive experience > Health care.The evaluation result showed that the comprehensive evaluation level of the water-saving plant,the material-saving plant and the land-saving plant were mainly concentrated in the II and III levels,which illustrated that the high quality community was less and the plant landscape still had a larger space for improvement.In the water-saving and land-saving plant communities,the structure of arbor-shrub-herbage complex layer structure or the forest structure had the highest index.In the material-saving type,the composite index of plant communities with high proportion of native plants,low maintenance requirements,strong stability and few pests and diseases was the highest.Based on the evaluation results,the community types with the higher comprehensive index in the water-saving,material-saving,land-saving plant landscape sample were analyzed in detail,which provided reference basis for model construction and case design in the later section.(3)Community model construction and optimization in Tianjin city parksBased on the evaluation results,the paper proposed a selection strategy for the water-saving,the material-saving and the land-saving plant material.For the water-saving plant,the entire research samples were graded in the light of the drought tolerance.Drought tolerant plants were screened out according to the results of the drought tolerance and the climate and the dominant plants in Tianjin.For the material-saving plant,all the samples were first classified as nativeplants and exotic plants,and then the native plants,the production plants and the fast growing plants were screened out.For the land-saving plant,according to the different modes of the complex plant community and the vertical planting,the corresponding suitable plants were selected.Based on the plant selection analysis and the evaluation,the plant landscape pattern accompanied with the water-saving function,the material-saving function and the land-saving function were summarized.Finally,the community with lowest composite index was optimized to provide reference for the construction and reconstruction of resource-saving plant landscape design in Tianjin city parks.