CONCENTRATIONS AND AMONG-COMPOUND CORRELATIONS OF INDIVIDUAL PHENOLICS IN WHITE BIRCH LEAVES UNDER AIR-POLLUTION STRESS

To detect early symptoms of heavy metal pollution in birch (Betula pub escens Ehrh.) trees, we studied foliar concentrations of phenolic comp ounds in polluted and control areas around the Harjavalta copper nicke l smelter, SW Finland. Phenolic compounds were quantified by analytica l high performance liquid chromatography. The total content of individ ual phenolics was 21% higher in samples from the heavily polluted (400 -500 m from the smelter) area than on the control area. Differences in foliar concentrations of individual compounds between the study areas were significant for (+)-catechin, trans-3 -p-coumaroylquinic acidi q uercetin-3-O-beta-D-galactopyranoside and one gallotannin. Variation i n contents of phenolics was quite large, Among tree variances of indiv idual phenolics between control and polluted area differed significant ly in the case of seven compounds: 1-O-galloyl-beta-D-(2-O-acetyl)-glu copyranose, four gallotannins, neochlorogenic acid and quercetin-3-O-a lpha-L-(4 ''-O-acetyl)-rhamnopyranoside. Differences in pairwise corre lations between phenolic compounds in polluted and control areas indic ated competition between some gallotannins and p-coumaroylquinic acids on the polluted but not on control site. Concluding, in strongly poll uted areas atmospheric stress factors appear to affect accumulation of some plant phenolics in birch leaves, their variability as well as be tween-compound correlations. (C) 1998 Elsevier Science Ltd, All rights reserved.