Fig. 3. Concentrations of SO2-4 (µM) for the Storgama lysimeters shown as mean of two replicates: 
Heather "normal rain," • Heather "acid rain," 
Moorgrass "normal rain," 
Moorgrass "acid rain," F = frost, D = drought.
Fig. 3. Concentrations of SO2-4 (µM) for the Storgama lysimeters shown as mean of two replicates: Heather "normal rain," • Heather "acid rain," Moorgrass "normal rain," Moorgrass "acid rain," F = frost, D = drought.