VISUAL SYMPTOMS EXPRESSED BY SOME RUDERAL PLANT SPECIES IN RESPONSE TO ANTHROPOGENIC AIR POLLUTION IN NIGERIA'S GUINEA SAVANNA

Abstract

Plants, by virtue of their stationary growth habit are usually the first to respond to environmental stress factors including air pollution. Data on the visual symptoms exhibited by higher plants in response to anthropogenic air pollution under tropical Savanna conditions is lacking. In an attempt to document the patterns of visual injury induced by air pollution on foliage of higher plants, field observations were conducted. Preliminary data show that many of the ruderal plant species that grow in this ecosystem exhibited varying degrees and patterns of injury that appeared to be characteristic for each species. Such ranged from bleaching, to formation of necrotic lesions in varying visual patterns. Intensity of symptoms expressed generally suggested an increase with increased anthropogenic activity. The significance of these observations to developing a checklist of sensitive higher plants and their patterns of visual response that will serve as a field guide for use in assessment of environmental impacts of air pollution under tropical savanna ecosystems is discussed.