Heavy Metals and Sulphur in Needles of Pinus sylvestris L. and Soil in the Forests of City Agglomeration

Abstract

The content of sulphur and copper (Cu), iron (Fe), manganese (Mn), zinc (Zn) and of assimilation pigments in the needles of Scots pine (Pinus sylvestris L.) in the forests of Bydgoszcz, Poland was determined. The content of those metals and the activity of dehydrogenases (DHA) in the rhizosphere of the trees was assayed. The average total sulphur (TS) content in 2-year-old pine needles was 832.4 mg kg−1 d.w. No significant correlation was found between TS and Cu, Fe, Mn and Zn in needles and the content of assimilation pigments indicating no phytotoxic effect of sulphur dioxide (SO2) and metals on Scots pine. The content of metals in the needles pointed to an inconsiderable degree of human impact. The soils in the surface layer were not contaminated with heavy metals. With the principal component analysis (PCA) two principal components were identified which accounted for 68% of the total change in variation. The variables that determined the principal components were the soil content of organic carbon (TOC), total nitrogen (TN), TS and sulphates (SO42−), the soil content of Mn, Zn, available forms to plants of Cu, Mn, and the content of Cu, Fe in needles.