1993 Volume 19 Issue 3 Pages 159-165
In order to study the effect of roadside planting in filtering atmospheric pollutant, wind tunnel experiment andfield study were conducted. Leaves of four species of trees were exposured in the tunnel at different windvelocities and their adsorption of particles were measured. In the road side of highway, adsorption of metal (Zn, Ca, Mn, Fe) by leaves of two tree species (Pasania edulis Makino and Ilex rotunda Thunb.) were also measured.
As results of tunnel experiment, we found adsorption of particles by leaves decreased in the order Pinus thunbergii Parl, Neriurn indicum Mill, Pasania edulis, Quercus rnyrsinaefolia Blume. The volume of adsorbedparticles were influenced by the nature of leaf surface where hairy leaves, rough and sticky leaves being moreefficient at adsorption of particles than smooth one. The volume of adsorbed particles increased with windvelocities and the increasing rate was the highest on Pinus thunbergii.
From the field studies, we found that the adsorption of metal by old leaves were higher than new one. Itprobably due to old leaves being exposured to atmosphere longer than new one. Seasonal variation of metaladsorption were influenced strongly by rainfall rather than concentration of suspended particulate matter.Generally, the volume of adsorbed particles tended to increase when it was small rainfall.
