Oxidant Air Pollution Impact to the Forests of Eastern United States: A Literature Review

摘要

This report presents a review of past studies that have attempted to delineate measurable and/or possible impacts of photochemical oxidants on the forests of Eastern United States. Sources of oxidant precursors and subsequent long distance transport phenomena are reviewed and documented. A brief historical treatment of eastern white pine responses to air pollutants is followed by an up-to-date evaluations of current air pollution measurements and associated impacts. Potential threats to eastern forest tree species are reviewed through a comparison of various fumigation studies in laboratory and field situations. The concept of hidden injury is discussed as being a possible major impact problem facing analysis of real losses. The authors present evidence that would suggest that many forest tree species indigenous to the Eastern United States may already be detrimentally impacted by previous high oxidant episodes. They further suggest that even more drastic and only long term reversible effects to the forest ecosystem will follow a trend of increasing oxidant air pollution in many major forested regions of this area of the United States.