Effects on Photosynthesis, Carbon Allocation, and Plant Growth Associated With Air Pollutant Stress

Abstract

Over the past 30 to 50 years, extensive literature has accumulated concerning air pollutant effects on plants. The relative degree of phytotoxicity of the common pollutant gases is known, and the potential for effects on many botanical classes of plants is understood somewhat. Knowledge is at a point where attempts are being made to assess and predict the effects of current or projected air pollutant levels on the growth or productivity of vegetation. The most successful attempts have been made with crops because the most extensive data are available in this area. The National Crop Loss Assessment Network (NCLAN) has made noteworthy contributions in the areas of generating empirical, field-based, dose—response data and of economic assessments (Heck et al., 1982; 1984; Adams et al., 1985). But, even in the case of assessment of crop losses due to air pollutants, it has become apparent that insufficient data or understanding exist to make predictions with a high degree of confidence. The NCLAN effort has clearly identified the need for additional information in the form of dose—response data concerning the interaction of air pollutants with other environmental variables and the need to establish the functional relationships between air pollution stress and plant growth and yield.