Technical Bulletin No. 0576: Response of Loblolly Pine Seedlings to Ozone Over Three Growing Seasons

A three-year study of chronic effects of ozone, a photochemical air pollutant, on field-grown loblolly pines was completed in late 1987. In the spring of 1985, seedlings from four full-sib families were planted in field plots, and open-top, plastic-covered chambers were placed on each plot. Over the next three growing seasons, the seedlings were exposed to six different ozone concentrations ranging from approximately 0.5 to 2.0 times the concentration in ambient air during the hours of 8:00 a.m. to 8:00 p.m. (7 days per week for 5 to 6 months in each growing season).