Toxic elements and energy accumulation in topsoil and plants of spruce ecosystems

Abstract

The objective of this research was to evaluate trends and relationships of energy and toxic elements accumulation in A-horizon (the depth of 0–5 cm) of soils and in selected plants of the hemioligotrophic (Dystric Cambisols) and oligotrophic (Skeletic-Rustic Podzols) spruce ecosystems situated along transect (750–1110 m a.s.l.) in the NP Slovenský raj (Eastern Slovakia). The results showed that EU limit values of risk elements in agricultural soils were exceeded for Cu and Cd at the altitude of 750–760 m a.s.l., and in case of Cd also above 1000 m a.s.l. Relationship between energy and toxic elements in soils revealed that with an increasing amount of energy, contents of Zn and Cu significantly declined with altitude (r > –0.5 or r > –0.9). The background value of Cu was exceeded in all plants, that of Zn for Dryopteris filix-mas and Rubus idaeus. Furthermore, excessive accumulation of Cd was revealed by all plants. Cu contents in soils were dominant in determining Cu uptake for Vaccinium myrtillus (r > 0.5); Zn and Cd for V. myrtillus (r > 0.6), D. filix-mas (r > 0.5 or r > 0.8) and Fagus sylvatica (r > –0.8 or r > –0.5); Zn also for R. idaeus species (r > 0.4). The soil-plant transfer coefficients higher than 1 hinted R. idaeus on the plots at the altitude of 960 m a.s.l. (Cd 1.1, Cu 1.2, Zn 3.1), which appears as an excellent native indicator of forest ecosystem contamination.