Bioindication of Air Pollution by Chlorophyll Destruction in Plant Leaves

Abstract

Young spruce plants, barley and alfalfa were exposed to polluted air in test chambers at a site in Stuttgart, West Germany. The effects on the chlorophyll [Chl] content and the pheophytin content were compared with control plants. Under field conditions, Chla and Chlb decompose with almost equal rapidity. Changes in the Chla:Chlb ratio are not suitable indicators of the influence of air pollution. After pollution was allowed to influence the plants over a long period, no pheophytin could be detected (not even at a monthly mean SO2 value of 0.13 mg m-3 air in winter). Determination of the pheophytin content cannot, therefore, be used to indicate the presence of harmful acid gases. The reduction in Chla as compared to control plants should be taken as the indicator of slight to moderate air pollution.