Tree Study Criticized; Researcher Defends It
A recent Times article cites a study that implicates certain landscape trees as a significant source of hydrocarbons; and, hence, air pollution.
One such popular tree, the liquidambar, was said to be a prime offender. No mention was made, however, that this particular tree is deciduous so that for the considerable period it is dormant (leafless), it emits no hydrocarbons.
More important, deciduous trees, when strategically located near dwellings, provide shade during the summer and allow for passive heating by the sun in the winter. Cooling and heating accomplished in this manner do not generate smog as would otherwise occur with the use of air conditioners and furnaces. In this context, then, the liquidambar tree is probably hydrocarbon emissions neutral.
Solutions for our air quality problem demand clear thinking, not clear cutting.
DR. WILLIAM L. CORBIN
Los Angeles
