Content of potentially toxic elements in herb species of spruce ecosystems affected by air pollutants

The contamination of Spodic Cambisols and selected herb species (Dryopteris dilatata, Luzula luzuloides, Prenanthes purpurea, Rubus idaeus, Senecio ovatus and Solidago virgaurea) by potentially toxic elements (Fe, Mn, Cu, Cr) issuing from polluted atmosphere was studied in spruce stand and parallel clear-cut area on the locality Stolíky situated in the buffer zone of the NP Slovensky raj close city Spi ská Nová Ves. The element contents determined in extracts of soil samples by 2 mol. dm-3 HNO3 were the following (mg kg -1 d.w.): Fe 3600--4300, Mn 1100--1300, Cu 81.1--100.6, Cr 1.16--2.00. The contents of elements in aboveground phytomass of dominant herb species ranged as follows (mg kg -1 d.w.): Cr 0.052--0.419, Cu 8.6--22.4, Fe 70.2--191.0 and Mn 1043--3457. Increased amounts of Cu and Mn (compared with the background values) were ascertained in all herb species, whereas the contents of Fe were higher only in Luzula luzuloides (clear-cut area) and Prenanthes purpurea (spruce stand) species and Cr contents were lower than background value. The values of Fe:Mn ratio (0.03--0.12) were markedly lower, while the values of Fe:Cr (403--1867) and Cu:Fe (0.086--0.203) ratios were substantially higher compared with the normal values in herb species and they indicate disturbance in herb nutrition and nutrient cycling in the spruce ecosystems.