The Effect of Air Supply on Apparent Photosynthesis

Abstract

Photosynthetic rates of the entire shoots of seedlings of Pinus taeda, Cornus florida, and Liriodendron tulipifera were measured over a range of rates of air supply. At the end of the range, CO2 was depleted as much as approx. 32%. Rate of photosynthesis increased hyperbolically with rate of air supply and linearly with mean CO2 conc. over this range. It is suggested that the differential responses of the photosynthetic mechanisms of different spp. may be, at times, an important factor in altitudinal distr.