| Atmospheric aluminum (Al), emitted from a coal-fired emission source, was examined in terms of its deposition pattern, interaction with surrounding oak (Quercus spp.) canopies and stems, and integration into the underlying soil mantle. A southwestern Illinois electric power plant was established as the center of the study area and 20 field sites were distributed along 4 linear transects (radiating away from the center) at approximately 1, 2.5, 5, 10, and 20 km from the emission source. Two study trees were selected per site.;At each site, bulk open and throughfall precipitation were collected by PVC trough gages while stemflow was captured by polyethylene collars. Soil water samples were collected by suction lysimeters at depths of 30 and 60 cm. Aqueous samples were gathered twice monthly from May, 1987 through September 1988. Tree foliage and floor litter samples were compiled at the beginning and end of 1987 and 1988 growing seasons. Soil samples from 4 selected horizons were extracted from soil pits.;Analytical determination of aqueous Al was achieved by a P-E GFAAS system. Filtered samples were differentiated into 3 Al groups: total Al, complexed Al, free Al. Plant and soil samples were analyzed by A&L Agriculture Labs in Memphis, Tennessee.;Results indicated that no localized zone of intensified Al deposition occurred around the emission source. Average total Al in the open precipitation was in trace amounts (41.3 ppb), however, over 44,000 kg of total Al were deposited from the atmosphere within the study area during the sample period. Oak canopies enriched the Al concentration (ppb) by two fold and the input load (kg/ha) by almost 40%. Degree of enrichment varied among study trees. Accumulation of Al into the foliage was noted during both growing seasons. Stemflow Al concentration was enriched by over 3 fold and was directly influenced by the emission source. Litter layer appeared to serve as an Al retention system. Exchangeable Al (ppm) in the soil increased with depth while soil water Al concentration (ppb) decreased with depth. |
