Whole-Plant Carbon Allocation and the Effects of Ozone Fumigation on Loblolly Pine (Pinus taeda)

Abstract

Loblolly pine (Pinus taeda) seedlings were grown under ambient and twice ambient ozone levels to determine the seasonal patterns of carbon allocation and the effects of ozone on that allocation. Aboveground and belowground biomass was determined and the foliage, stem, coarse root, and fine root components were analyzed for ^C-labelled photosynthate at each harvest. In the seedlings grown under ambient ozone levels the aboveground growth occurred most rapidly during the earlier months of the growing season while root growth occurred most rapidly at the end of the growing season. The seedlings grown under twice ambient ozone levels showed the same seasonal growth patterns. There were no statistically significant effects of elevated ozone levels on either biomass components or carbon allocation.