PM1mass Concentration Change Of Conifer And Broadleaf Urban Forest And Its Correlation With Meteorological Factors

In Beijing Olympic forest park south north fifth ring road of shelter belt (Poplar, Pinus tabulaeformis Carr.) as the research object, five were arranged by both inside and outside the forest belt observation forest inside and outside of PM1 concentration change, analysis of forest inside and outside of PMi concentration variation characteristics and its response to meteorological factors. Results showed that:1) Two kind of urban forest annual change trend of air PMi concentration in the air is close, basically the highest is in February, Aguest and December, the second-highest in April, May, July, September; and in the middle of PMi concentration is in March, June and October; the lowest levels of PMi concentration is in January and November.PMi concentration of this change is conform to climate change, human activity and plant growth conditions. From the perspective of the change trend of different seasons, two kinds of urban forest in PM1 concentration showed highest concentration in winter, the second-highest concentration in summer, PM1 concentration in spring and fall is the lowest. 2) Between the two kinds of different sites in forest PMi concentration change trend is consistent, but the same location of two forest zones of PM1 concentration change law is different. Before 8:30 am and during 12:00～14:00 in the noon, the PM1 concentrations in the forest of Pinus tabulaeformis was higher than the forest of Poplar, other times PMi concentration were lower than that of Poplar.3) PMI mass concentration inside the forest is negatively related with the temperature and the wind speed,and positively correlated with relative humidity, Atmospheric pressure and the direction of the wind.4) Under the condition of "continuous sunny" weather, forest block adsorption on particulate matter; "Sunshine after the rain", "clear to overcast", "sunny after the fog" this three kinds of weather conditions, PM1 fine particulate matter such as easier to accumulation and enrichment in the forest; "More windy day" forest internal and external quality of PMi concentration is low, the small environment conducive to the formation of turbulence in the forest, so as to accelerate the settlement of PMi in the forest.