Atmospheric deposition during the growing season contributes one-third or more of the estimated total flux of lead, zinc, and cadium from the forest canopy to soils beneath an oak stand in the Tennessee Valley but less than 10 percent of the flux of manganese. The ratio of the wet to dry deposition flux to the vegetation during this period ranges from 0.1 for manganese to 0.8 for lead to ∼ 3 to 4 for cadmium and zinc. Interactions between metal particles deposited on dry leaf surfaces and subsequent acid precipitation can result in metal concentrations on leaves that are considerably higher than those in rain alone.
