THE PARTICULARITIES OF CHEMICAL POLLUTANTS ACCUMULATION IN DIFFERENT COMPONENTS OF FOREST ECOSYSTEMS IN MOLDOVA

The study performed in 34 forest ecosystems in the Republic of Moldova indicates that there are certain particularities concerning differential accumulation of heavy metals in abiotic and biotic ecosystem components and possible sources of pollution. The results of the chemical analysis of the six studied chemical elements (Cu, Zn, Cd, Pb, Cr and Ni) show that none exceeded maximum permissible concentration in the soils of our forests. It has been evaluated that trees tend to accumulate Zn, Cu, Pb, Cd and Ni which is confirmed by high concentration of these elements in the litter of representative species. Mosses intensely accumulate Pb, Cd, Cr, whereas lichens proved to be the best accumulators of Cu, Pb and Cr. In particular, the litter layer and mosses accumulate better Cd than lichens do, which indicate the possibility of their use in monitoring of environment pollution with Cd. In all cases mosses and lichens accumulated more Cr than the litter does, which probably involves a cross-border penetration of the pollutant by air. Ni is accumulated better by trees, because the element content in the litter prevails over that in lichens and mosses. Its origin can be both ground and air.Taking into consideration investigated bio accumulator’s cumulative properties and distribution uniformity, the following species are recommended to be applied in the monitoring of ecosystems pollution with heavy metals within the Republic of Moldova: oak - Quercus robur, mosses - Hypnum cupressiforme, lichens - Parmelia sulcata and mollusks - Helix pomatia.