Precipitation totals, SO42- concentrations and delta(34)S ratios were measured in bulk (open area) deposition, beech (with some birch and ash) and spruce throughfall at 17 locations in the heavily polluted mountain-slope Jezeri catchment (490-924 m asl) over a 12-month period. Stream water S was analyzed monthly at seven altitudes. The delta(34)S ratios decreased in the order: bulk > beech > spruce > stream (1995 annual means across all altitudes were 5.7, 5.1, 4.2 and 4.0 parts per thousand, respectively). The differences were caused by different intensities of scavenging of isotopically distinct pollution-derived SO2 by tree canopies. The delta(34)S ratios of bulk deposition increased and delta(34)S ratios of spruce throughfall decreased with increasing altitude. The elevational gradients in delta(34)S ratios reflected the changing roles of local vs. distant air pollution sources along the slope. References: 15
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