Study On The Reduction Function Of Air Particulate Matter And The Screening Of Community Models By Plant Configuration Of Major Green Space Types In Guangzhou

The problem of atmospheric particulate matter pollution is becoming more and more serious,which is harmful to human health.Urban greening can significantly remove air pollutants,improve environmental quality,be beneficial to health,and play an important role in reducing particulate matter pollution.In order to study the detention effect of urban green space on atmospheric particulate matter,this paper takes typical green space types in Guangzhou urban area as the main research object.Through field investigation,sampling,data collection and laboratory analysis,it analyses the reduction function of PM_2.5particulate matter by different green space communities,the relationship between the structure characteristics of green space communities and atmospheric particulate matter concentration,and the dust detention ability of main tree species.The research concludes the following conclusions:（1）Guangzhou’s community green space is suitable to refer to the tree species allocation mode of Guangzhou East Railway Station Square green space,that is,according to the tree-shrub-grass multi-layer structure,tree layer tree species can be considered to choose ficus microcarpa,ficus,mango and so on;Guangzhou’s park green space is suitable to refer to the configuration mode of Guangdong tree park,that is,the community structure is multi-layer structure,species composition is rich,diversity is high,community canopy density is high.High.Although Ficus macrophylla and Ficus alpina have better control effect on TSP and PM_2.5,there are many shortcomings as street trees because of their growth characteristics.In combination with landscape,we recommend some tree species,such as Tabebuia chrysantha,Mango and Delonix.（2）The characteristics of green space community structure affecting atmospheric particulate matter concentration include green space canopy density,cumulative crown volume of trees and height under branches of trees.Among them,PM_2.5 reduction rate was positively correlated with greenbelt canopy density and tree crown volume,and negatively correlated with tree height under branches.The arbor layer and shrub-grass layer of green space have interaction on PM_2.5 reduction rate.In order to give full play to the role of urban green space in regulating atmospheric particulate matter,urban green space should aim at building a community with high canopy density,and tree species selection should be based on tree species with larger crown volume and lower height under large branches.（3）There were significant differences in dust retention among the same species.Among them,Saussurea chrysantha and Mei pistil were the trees and shrubs with the highest adsorption capacity.Among the tested trees,Melia azedarach,Kapok cotton and Bruguilla microphylla had poorer adsorptive capacity for large diameter particles,while Bauhinia chinensis,Ficus macrophylla,Mango,Kapok cotton and Bruguilla microphylla had poorer adsorptive capacity for small diameter particles.Among the shrubs tested,besides pistil flower,Huang Zhao also had certain adsorption effect on large diameter particles,while Euphorbia chinensis and Cinnamomum Cassia had the worst adsorption ability.For small diameter particles,there was no significant difference among the tested species.In the selection of tree species for urban greening,besides the landscape effect,the dust retention ability of tree species should also be taken into account in order to alleviate the problem of urban air pollution to a certain extent.Species such as Sambucus suzuki,Mei pistil and Siberia Alba have higher adsorption capacity for atmospheric particulate matter,so they can be mostly used in urban greening.