Nutritional response of loblolly pine exposed to ozone and simulated acid rain

Authors

Timothy R. Baker, Department of Forest Resources, Box 8008, North Carolina State University, Raleigh, NC
H. Lee Allen, Department of Forest Resources, Box 8008, North Carolina State University, Raleigh, NC
Michele M. Schoeneberger, University of Nebraska - LincolnFollow
Lance W. Kress, USDA Forest Service

Date of this Version

August 1993

Comments

Published in Can. J. For. Res. 24: 453-461.

Abstract

The effects of ozone and simulated acid rain on the aboveground nutrient composition of loblolly pine (Pinus taeda L.) seedlings were studied in a 2-year open-top chamber experiment in the Piedmont of North Carolina. Multivariate analysis of variance tests indicated significant ozone response in the 2nd year but no significant simulated acid rain effect in either year. No interaction among treatments was detectable. Seedlings responded to increasing ozone exposures with increasing concentrations of nitrogen, phosphorus, potassium, magnesium, and calcium in the stem, branches, and foliage. The response of increased nutrient concentration was associated with decreased total biomass accumulation. The nutritional responses were most prominent in late season flushes of foliage and are probably related to ozone-induced premature abscission of early-season flushes. High nutrient concentrations in the stem, branches, and late-season flushes of trees exposed to elevated ozone levels suggest retranslocation and slower growth rates resulted in better aboveground nutrient status and lower nutrient demand from the soil.