Study On Evaluation And Construction Strategy Of Greening Landscape Of Street Trees In Central City Of Chongqing

The greening landscape of street trees is an important part of urban landscaping,and it is also the image display window of the city.At present,with the rapid development of social economy,there are higher requirements for the construction of urban ecological environment.However,the current landscape construction of street trees lacks the guidance of relevant theories.The current landscape has problems such as duplication of tree species,simplification of configuration methods,and insufficient management and maintenance intensity.At present,there are few related researches on the greening landscape of street trees in Chongqing,and as a mountain city,the greening of street trees in Chongqing has its particularity.In view of this,this study is aimed at the research on the greening of street trees in the central city of Chongqing.This article systematically summarizes and combs the related concepts of urban street trees,combs the basic subject theory and the research progress of street tree greening,and selects the greening of street trees in 141 transects of 107 roads in the central city of Chongqing as the research object,and its greening status and planting Investigate and analyze the form,configuration mode,road space attributes,etc.,and put forward the problems existing in the current situation of street trees.The AHP analytic hierarchy process is used to comprehensively evaluate the street tree species that appeared in the survey,screen out the dominant street tree species that appear,and sort out the dominant tree species suitable for Chongqing area configuration through the data.The study uses the SBE method-SD method to evaluate the beauty of 42 road-like street tree landscapes,and conducts landscape evaluation and grading.Finally,based on the survey and research results,the optimization strategy and model recommendations for street tree greening landscape construction in Chongqing area are proposed to provide scientific theoretical guidance for the future urban road street tree landscape construction and improvement.The results of the current study are as follows:(1)According to the current survey and statistics,there are 44 species of street trees belonging to 24 families and 38 genera.Among them,there are 23 species of evergreen trees and 21 species of deciduous trees.The ratio of evergreen and deciduous leaves is 1:0.91,and the number of evergreen and deciduous species of street trees.More balanced.A total of 33 species of native roadside trees appeared in the survey transect,and a total of 11 species of street trees were introduced.The ratio of the number of native species introduced was 1:0.33.The native tree species are widely used and have obvious zonal characteristics.According to the analysis of the frequency of species application,the very common tree species such as Ficus sibiricum,Pueraria lobata,Cinnamomum camphora,Ginkgo biloba,Magnolia,crape myrtle have a wide range of applications,while the frequency of occasional tree species such as silk sunflower,false betel nut,and taberus is very rare.,The species richness needs to be improved,and there is a phenomenon of duplication and simplification as a whole.In terms of viewing characteristics of street trees,flower viewing and leaf viewing tree species account for a relatively large proportion,while fruit viewing and stem viewing tree species are relatively lacking.The seasonal landscape is mainly composed of spring and summer flowers,autumn and winter viewing fruits and leaves.The overall landscape With red and white as the main hues,the color richness needs to be enhanced.(2)In terms of street tree landscape configuration,the planting form of green belt combined with tree pond is the most widely used,followed by tree pond and green belt planting,and the mixed arrangement mode combining evergreen and deciduous tree species accounts for the largest proportion.The landscape management and maintenance of street trees is mainly carried out from the aspects of pruning and cutting poles,pest control,main trunk reinforcement,and nutrient supplementation.The main road maintenance intensity is the largest,and the branch road maintenance intensity is the smallest.The overall post-maintenance work needs to be improved.Regarding planting norms,the irregularity of sidewalk tree planting is the most serious.There are problems such as too small plant spacing,too close to municipal facilities and buildings,and too narrow planting ponds and planting bands.According to the author’s questionnaire survey and statistics,most of the interviewees believe that the greening of street trees in downtown Chongqing has problems such as low plant species richness,similar configuration forms,lack of change,etc.,and there is still much room for improvement in the overall landscape.(3)In the comprehensive evaluation of street tree greening species,the four major categories of street tree landscape,resistance,practicability and economy are established as the criterion layer,and there are 15 index layers,and the weight system is based on the judgment matrix of the AHP analytic hierarchy process.Establish importance analysis system.In the calculation of the relative weight of the criterion layer(B)relative to the target layer(A),after the consistency test,the respective relative weight value W is obtained,and the result of the weight calculation is analyzed.According to the results of selection and evaluation,they are divided into grades.Among them,there are a total of 11 excellent tree species,which are recommended as backbone tree species;the evaluation grade is a total of15 tree species,which are recommended as key tree species;the evaluation grade is a total of general and poor tree species.18 species,recommended as general tree species.Through data collection and sorting,and summarized according to evergreen tree species and deciduous tree species,the dominant tree species suitable for planting in Chongqing area are recommended.(4)In the evaluation of street tree greening landscape,research shows that the judges of the garden professional group and the non-professional group have a high consistency in the aesthetics and evaluation of the beauty of the street tree landscape.The difference analysis of the samples shows that among the survey samples of different grades of roads,the main road sample has the highest SBE standardization value and the branch road has the lowest score;among the different vertical hierarchical structure samples,the arbor,shrub,and grass have the highest score.,The single tree structure has the lowest score.Combined with the SD method landscape factor evaluation,the beauty degree regression model is obtained.The model is SBE=-1.309+0.067×X2+0.195×X3-0.046×X4-0.088×X5+0.140×X6+0.155×X7+0.219×X8-0.137× X9.Studies have shown that in the model of the beauty of the street tree greening landscape,the beauty of the plant form,the greenness,the sense of characteristics,the coordination of the landscape,the sense of space and the beauty are directly proportional,and the color richness and layering are inversely proportional to the beauty.(5)Based on the current situation investigation and research and related evaluation results,propose an optimization strategy for the street tree greening landscape in Chongqing.From the perspective of landscape ecological function,it is proposed: increase the number of applied species and increase the diversity of greening tree species;optimize the ratio of evergreen and deciduous tree species to create a street tree landscape that shades summer and winter;increase the application of dominant native and zonal tree species to increase the richness of life-type structure;Enrich the vertical landscape level and increase the diversity of configuration forms.From the perspective of landscape aesthetics,it is proposed: to create Chongqing’s regional characteristic landscape and shape the city’s business card;to strengthen the use of artistic techniques of plant landscape;to enrich seasonal landscapes and ornamental characteristics.From the perspective of landscape behavior psychology,it is proposed to create plant landscapes of suitable scale and usable by people.In terms of spatial scale,visual dynamics,color rhythm,temporal changes and environmental relations,the optimization points were put forward.Finally,from the perspectives of different layout forms,vertical hierarchical structures,functional requirements,road grades,and mountain topographic features,the optimization strategies for landscape construction were proposed.