The Growth of Two Forest Tree Species Adjacent to a Periodic Source of Air Pollution

Abstract

The effects of an isolated, periodically varied source of nitrogen oxides and sulfur dioxide air pollutants on the growth of two forest timber species was investigated. The annual production levels from 1941 through 1971 of the Radford Army Ammunition Plant (Arsensal), Radford, Virginia, were used as indicators of relative pollution emissions. The annual increment growth of 43 eastern white pine and 50 yellow poplar was determined to the nearest 0.05 mm with a dendrochronograph from 3.2 mm diam increment cores taken 1.37 m up from the base of each tree. An inverse relationship, significant at the 99.5% confidence level, was found by linear regression analyses to exist between the fluctuating production levels of the Arsenal and the annual increment growth of white pine and yellow poplar. Correlations significant at the 97.5% confidence level were found to exist between the annual increment growth of white pine and yellow poplar and the amount of seasonal and annual rainfall, respectively.