Abstract Three sites in north-east Scotland were selected to compare soil characteristics of acidification-sensitive sites under Calluna vulgaris heathland and afforestation. At each site, fences separate Calluna heathland from Scots pine plantation on podzol profiles evolved from granitic parent material on gentle slopes in the altitude range 200–500 m. In total, 30 soil pits were dug, with five for each land use-type at each of the three sites. Samples of each horizon were analysed for pH, sulphate adsorption/desorption characteristics, cation exchange properties, carbon and nitrogen contents, bulk density and texture. As expected, acidification to depth had occurred in the forest sites. However, although the forest soils at depth showed less capacity for sulphate adsorption, as might be expected from increased atmospheric aerosol and pollutant trapping and greater water interception loss under trees, they did not contain more PO 3− 4-extractable sulphate. This may reflect the combined effects of soil pH differences and changes in concentrations and composition of soluble organic matter upon sulphate adsorption, although interpretation is also complicated by textural differences between forest and heathland soils.