Soil and forest vitality as affected by air pollutants on the Kola Peninsula

Investigations on heavy metal and SO2 polluted forests in Kola peninsula indicated strong soil acidification at a distance of 20–30 km from the strongest SO2 emission source. Toxic concentrations of Ni and Cu in the soil organic layer was supposed to affect tree vitality. Stepwise regressions indicated strong negative effects on neddle loss, needle age classes and needle weight due to the accumulation of Ni. Direct effects of SO2 could not be evaluated. From comparison with industrial areas with more fertile and phosphorous rich soils it was concluded that the negative effects of heavy metals and SO2 could be counter-acted.