Research On The Influence Of Park Green Space On Particulate Matter And Blocking Capacity Ability In Shenyang

Plants have an important function of blocking the concentration of atmospheric particles.Park green space in different regions and plant communities of green space in Shenyang were taken as research objects.Measured the concentration of particulate matter（PM）in parks,plant communities,individual plants and conducts research from multiple perspectives.During May 2019 to July 2020,that conducted surveys of park green space in different regions and plant communities,as well as monitoring the concentration of PM.Simultaneously monitored changes in environmental factors such as temperature,relative humidity,and wind speed.At the same time,combined with the comparative analysis of meteorological data and air quality monitoring station data in Shenyang.Obtained the changes in the concentration of PM in parks green space in different regions and the ability of plant communities in green space to block the concentration of PM.The main conclusions are as follows:（1）Variation of PM concentration in different regions showed certain differences The concentration of PM in the park is basically lower than outside the park.The concentration of PM in the parks showed a"V"trend in winter,that is,the lower suburban parks,and the higher urban parks and outer suburbs parks;TSP and PM_1.0 showed a"urban-suburban"gradual decline trend in spring;TSP and PM₁₀ showed a gradual increase in the"urban-suburban"trend in autumn,while PM_2.5 was the opposite.The greatly comprehensive dust-retention capacity of different regions showed summer>spring>autumn>winter,and the suburban parks had the best dust-retention capacity for PM.Urban parks PM_2.5 was the main pollution composition in winter and summer.In suburban parks,PM_2.5 was the main pollutant in four seasons,and the proportion was higher than 50%.The composition of PM in the outer suburbs was more extensive in winter and spring,and the highest proportion of PM_2.5 was 75.44%in summer.There was a significant correlation between the concentration of PM and environmental factors in park green spaces in different regions.Among them,the concentration of PM had a positive correlation with relative humidity,and a negative correlation with wind speed and temperature.In spring,TSP was significantly affected by wind speed.In summer,the correlation between PM concentration and temperature wsa not significant,and wind speed was positively correlated.（2）The concentration of PM in different communities of park green spaces showed significant differences with seasonal variations The seasonal variations of PM concentration were winter>autumn>spring>summer.It peaked in December and January during central heating,and was the lowest in June.There was a clear downtrend in April.Good weather occurred from May to June,and the average concentration of PM_2.5 was 32.43μg/m³.The ability of different types of plant communities to block particles varies significantly.The coniferous and broad-leaved mixed forest had the highest ability to block particles,and the sparse forest grassland had the worst.Coniferous forests had strong blocking ability against PM_2.5,and broad-leaved forests had strong blocking ability against TSP.The blocking ability of broad-leaved forest was stronger in spring and summer,and that of coniferous forest was stronger in autumn and winter.（3）The difference in blocking functions of individual plants PM was obvious.Among 21species of plants coniferous species had greater dust retention capacity than broad-leaved species.Among them,Pinus tabuliformis had the best dust-retaining ability for particulate matter,and Acer mono had the worst.Ginkgo had better deferment ability to TSP and PM₁₀,but it was poor to PM_2.5 and PM_1.0.The concentration of PM was correlated with community characteristic indicators.Basically,the higher the tree height,plant number density and understory coverage,the stronger the ability to block particulate matter,but the diameter at breast height and crown width were opposite.The blocking capacitywas better at the time of85%of canopy density.