Effects of Landscape Tree Species and Their Arrangement on PM_(2.5) Sedimentation - A Case Study of Beijing, China

摘要

PM_(2.5), which refers to particles less than 2.5 μm in diameter, pose great health risks. Previous studies have mainly focused on the relationship between land utilization and air quality. Few studies have discussed the effects of landscape tree species on PM_(2.5) sedimentation and explored reasonable tree species arrangement for PM_(2.5) prevention. This study considered the polluted Beijing in China as the study site. This study investigated the PM_(2.5) sedimentation data of 10 shrub and 11 arbor species to understand the PM_(2.5) holding capacities of the landscape tree species. This study also obtained PM_(2.5) concentration data from 35 air quality monitoring sites. The results of linear regression analysis showed that (1) a closely linear relationship exists between PM_(2.5) concentration from air flow and PM_(2.5) sedimentation of various tree species in different seasons and sampling sites, and that (2) shrub trees possess better PM_(2.5) holding capacities than arbor trees in urban and heavy traffic areas, whereas arbor trees exert obvious effects on preventing PM_(2.5) pollution in rural areas. Thus, the proportion of shrub trees should be reduced in urban and heavy traffic regions, whereas that of arbor trees should be increased in rural areas. This study attempted to solve air pollution through landscape tree arrangement for PM_(2.5) sedimentation. The results of this study could serve as a guide for landscape tree species arrangement and plantation in Beijing and other cities.