Nutrient effects on responses of willow and alder to ozone
Nutrient status is known to influence plant response to air pollution. One goal of this paper is to synthesize the current understanding in this area by examining studies in the literature in which plants were raised under various nutrient regimes and exposed to O3. Another goal is to probe nutrient-air pollutant interactions with a simple plant system without rhizosphere symbionts. A final goal of this paper is to relate O3-nutrient interactions to the capacity for rhizosphere symbionts to influence plant response to O3. This involved exposing alder (Alnus serrulata Aiton. Willdenow) with and without root nodules formed by the nitrogen-fixing actinomycete Frankia to filtered air or O3. Thus high and low nitrogen treatments were provided by the presence and absence respectively of the rhizosphere symbiont.