Element concentrations in five <i>Sphagnum</i> species in relation to atmospheric pollution

Abstract

Shoots of five Sphagnum species were collected in Cumbria and transplanted into the bog surface at two sites, one in North Wales and one, a polluted site, in the southern Pennines. Tissue concentrations of nitrogen, phosphorus, potassium, sulphur, iron and lead were determined at intervals over an 18-month period. These concentrations increased markedly with the exception of potassium in the southern Pennine plants, but were little altered in North Wales. The largest increases were observed in nitrogen, ranging from 17.7 mg g−l in Sphagnum recurvum to 5.3 mg g−l dry weight in S. capillifolium. Bulk deposition of these elements and their concentrations in the surface peat were also determined. The results are discussed in relation to the paucity of ombrotrophic Sphagnum species in the southern Pennines today.