By decreasing both the temperature and the amount of pollutants in the atmosphere, trees can have a positive effect on air quality. This is significant since federal highway funds can be withheld from Atlanta and other metropolitan areas because of poor air quality. Ozone is a major contributor to poor air quality in urban areas. Perhaps an appropriate analogy would be the filter for a home air conditioning unit. If you remove the filter for the air conditioning unit, the cooling unit will become clogged with trash and will stop functioning.
Ionic materials comprise the major exhaust pollutants of vehicles.
Trees were able to remove large quantities of each type of material. Increased Water Run-Off. Commercial development substantially changes the topography of an area. The effect of the vegetation and soil is to slow the movement of water and to provide an opportunity for water to enter the ground. Development removes trees and other vegetation that soften the impact of rain.