Effects of Vertical Heights of Plant Community on PM_(2.5) Concentrations
Yu Lu;Wang Yujie;Sun Fengbin;Tong Qun;Shi Si;Yan Hai;Shao Feng;School of Landscape Architecture,Zhejiang Agriculture & Forestry University;School of Agriculture,Heilongjiang Bayi Agricultural University;Lin'an District Environmental Monitoring Station;School of Landscape Architecture,Beijing Forestry University;
In order to explore the changes in PM_(2.5) concentration in different vertical heights of different plant communities in winter and spring,the vertical gradient method was applied in three sample plots including the Beijing Olympic Forest Park carbon flux tower,the Jiufeng National Forest Park meteorological observation tower and Beijing Forestry University which was taken as a control point for research. The results show that the concentration of PM_(2.5) in the plots varied in different vertical heights,i. e.,above the canopy( above the tower,12 m) the canopy( the middle of the tower,9 m) below the canopy,above the ground( under the tower) in spring. The daily change of PM_(2.5) concentration basically showed the shape of"inverted N",which went up to the peak from 06 ∶ 00 to 10 ∶ 00 in the morning,the decrease from 10 ∶ 00 to 14 ∶ 00,and the increase from 18 ∶ 00 to 22 ∶ 00. The concentration of PM_(2.5) at the three layers in the Jiufeng National Forest Park meteorological observation tower was ordered as upper tower middle tower lower tower. The concentration of PM_(2.5) in the three plots was sequenced as Beijing Forestry University Olympic Forest Park Jiufeng National Forest Park at the same height. PM_(2.5) values at the three plots were higher in winter than in spring.