Discussion On The Application Of Perennial Ground Cover Plants In The Comprehensive Park Of Chongqing Main City

Park green space is an important part in urban ecosystem,in alleviating urban environment problems and improves the quality of urban green space plays a positive role,in recent years,the perennial cover plant because of its rich resources and good ecological benefit,high ornamental value,become an important material of park plant landscape,caught the attention of the height of the garden workers.Therefore,based on the basic theory of ground cover plant-related,this paper conducted a general survey of perennial ground cover plants in 21 comprehensive parks in the main city of Chongqing,and selected 128 typical plots for key investigations.The species composition,ornamental characteristics,application frequency,growth potential and configuration characteristics of perennial ground cover plants were analyzed,and the AHP-GRAP comprehensive evaluation model was used to comprehensively evaluate the application quality,and the application of perennial ground cover plants was discussed.The problems and optimization suggestions are intended to provide reference for the application of ground cover plants in Chongqing.The main research results are as follows:(1)There are a total of 170 perennial ground cover species(including varieties)in the main parks of Chongqing's main urban areas,belonging to 72 families and 130 genera.Among them,there are 77 species of dwarf shrubs,77 species of perennial herbaceous ground cover plants,13 species of vines,2 species of ferns,and 1 species of bamboo;44.12% of the species are concentrated in 13 families such as Liliaceae and Oleaceae;Evergreen land is dominated,the ratio of evergreen to fallen leaves is about 4:1;the land of perennial township is 68 kinds,accounting for 40%,but the actual application in the park is less.(2)There are 110 kinds of common ground cover flowering plants in the main urban area of Chongqing,accounting for 66.47%.The flowering period is mainly concentrated in summer,the color is mainly red and white,and the blue-violet and multi-color is applied less;the foliage plants are mainly colored leaf plants,a total of 33 species,accounting for 19.41%,mainly variegated and red plants,lacking purple and silver ground cover plants.Fruit-viewing and aromatic ground cover plants are used less,but their development and utilization prospects are good.(3)By analyzed the frequency and important value of 113 perennial ground cover plants in the plot,it is known that Loropetalum chinense var.rubrum Yieh and Ophiopogon japonicus(Linn.f.)Ker-Gawl.are extremely common species,and the application frequency is 78.94% and 87.5%,respectively,which is much higher than other ground cover plants.There are 28 common species,41 less species and 42 rare species.The less species and rare species account for 73.45%,indicating that such ground cover plants are less practical and have greater potential for development and utilization.The woody class ground cover plants application frequency and important value of the top with Loropetalum chinense var.rubrum Yieh,Photinia × fraseri Dress,Rhododendron × pulchrum Sweet,Rhododendron × pulchrum Sweet;Herbaceous kind of rank has Ophiopogon japonicus(Linn.f.)Ker-Gawl.Pilea cadierei Gagnep.Nephrolepis cordifolia(L.)C.Presl and so on;the liana ground cover plants such as Parthenocissus tricuspidata(Sieb.et Zucc.)Planch,Mucuna sempervirens Hemsl.and Rosa multiflora var.cathayensis Rehd.et Wils.were ranked in the top three.This kind of ground cover plants are mostly traditional ground cover,which has been applied frequently and used widely in Chongqing park green space,and its importance is obvious.(4)By calculated the average growth index of 113 perennial ground cover plants in the plot,and used cluster analysis to divide their growth potential into three grades of excellent,good and bad.Among them,there were 40 species and 67 species of plants with excellent growth potential,and only 6 species of ground cover plants had poor growth potential,indicating that most of the ground cover plants grew well in the green space of Chongqing Park.(5)In terms of perennial ground cover plant landscaping: according to the planting form,it can be divided into planting,planting,color block and flower field planting.Among them,planting and color block planting are the most common;the main landscaping techniques are mainly flat landscaping techniques.Three-dimensional landscaping is relatively rare;according to the different functional space types of green space,it can be divided into plant main landscape space,waterfront green space,road green space,architectural green space surrounding the building,and square green space.In general,different spaces have different emphasis on plant selection and configuration,and the overall viewing effect is better.(6)Using AHP-GRAP comprehensive evaluation model of comprehensive evaluation of quality of perennial groundcover plants application get rule layer factor weight sorting as follows: ecological adaptability > growth status > ornamental characteristics > development and application potential,and index layer order in the first three are coverage,high temperature resistant,resistant to negative,suggests should consider its ecological adaptability mainly cover plant selection and ground coverage.According to the weighted correlation degree,the quality of the ground cover application is divided into three grades: 124 kinds in grade I,39 kinds in grade II,7 kinds in grad III,Rhododendron × pulchrum Sweet,Osmanthus fragrans var.semperflorens,Loropetalum chinense var.rubrum Yieh,Nandina domestica Thunb.,Pilea cadierei Gagnep.Argyranthemum frutescens(L.)Sch.Bip.and so on application quality is good,may in Chongqing park key promotion application.(7)There are still many problems in the application of perennial ground cover plants in the main parks of Chongqing main city,mainly reflected in the relatively concentrated application types,the main varieties are similar,the ground cover plants have a single effect,neglecting the ecological habits of the ground cover plants,and the post-maintenance work needs to be strengthened.In the future application of ground cover plants,more attention should be paid to rational selection of varieties,optimization of landscape allocation,emphasis on ecological benefits,and strengthening of conservation work.