Response Of Growth And Gas Exchange Of Tulip Poplar (LIRIODENDRON TULIPIFERA L.) Seedlings To Ozone Exposure

Tulip poplar (Liriodendron tulipifera L.) seedlings were exposed to a gradient of ozone for two seasons in open-top chambers at the Uplands Field of larger trees. Diurnal rates of photosynthesis were significantly lower in 2.0 X ambient in September of 1991, due mainly to reduced rates in older leaves. Few treatment effects were found in the light or CO2 curves, with the exception of photosynthetic capacity and intercellular CO2 concentration at light saturation, which were reduced by ozone in June of 1991.