@article{baker_allen_1996, title={Ozone effect on nutrient resorption in loblolly pine}, volume={26}, ISSN={["1208-6037"]}, DOI={10.1139/x26-184}, abstractNote={ A three-year study on the effects of chronic exposure to elevated ozone on loblolly pine (Pinustaeda L.) was conducted at a site in the Piedmont of North Carolina. Open-top chambers were used to control six levels of ozone, from 0.50 times ambient to 3.0 times ambient ozone concentration, on two open-pollinated families with suspected differences in sensitivity to ozone. Nutrient concentrations and contents were measured in fascicles obtained before and after abscission. Ozone strongly accelerated fascicle abscission and also tended to increase most nutrient concentrations in both pre- and post-abscission fascicles. There was, however, no significant impact of the ozone treatment on the amounts of nutrients resorbed during abscission. These data suggest that nutrient resorption associated with elevated ozone exposure followed a pattern more closely approximating accelerated senescence rather than premature abscission per se. The two open-pollinated families did not differ in nutrient resorption but did have isolated differences in the pre- and post-abscission fascicle concentrations. }, number={9}, journal={CANADIAN JOURNAL OF FOREST RESEARCH}, author={Baker, TR and Allen, HL}, year={1996}, month={Sep}, pages={1634–1642} }
 @article{baker_allen_schoeneberger_kress_1994, title={NUTRITIONAL RESPONSE OF LOBLOLLY-PINE EXPOSED TO OZONE AND SIMULATED ACID-RAIN}, volume={24}, ISSN={["0045-5067"]}, DOI={10.1139/x94-062}, abstractNote={ The effects of ozone and simulated acid rain on the aboveground nutrient composition of loblolly pine (Pinustaeda 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. }, number={3}, journal={CANADIAN JOURNAL OF FOREST RESEARCH-REVUE CANADIENNE DE RECHERCHE FORESTIERE}, author={BAKER, TR and ALLEN, HL and SCHOENEBERGER, MM and KRESS, LW}, year={1994}, month={Mar}, pages={453–461} }