Sulphur dioxide uptake and the leaching of sulphates from a pine forest.
The av. daily deposition velocity of SO2 onto a canopy of pine [Pinus sylvestris/P. nigra var. maritima] in Nottinghamshire, UK, in a dry summer (1975) was estimated to be 0.004 m/s by a flux gradient method. SO2 transfer was affected by the surface resistance rc (which determines uptake). Comparison of rc for SO2 with that for water vapour transfer suggests that stomatal control may be an important influence on the rate of deposition. Comparison of the sulphate content of rainwater before and after passing through a forest canopy indicates that: sulphate deposited dry on foliage may be significantly leached by rainwater; and rainfall enrichment is proportional to the airborne concn. of SO2. From author's summary.