Variability of Cation-Exchange Capacity (CEC) of Fen Peats in Vertical Profiles from Eastern and Central Poland in Relation to Function of Peatlands as Natural Geological Barriers

An analysis of cation-exchange capacity(CEC) variability of peats is presented in vertical pro files from eastern and central Po land. CEC values were com pared with ash con tent (Ac), pH and CaCO3 content. Eight peatlands were selected for re search in the fol lowingareas: War saw Plateau (2 objects), Siedlce Plateau (2 objects), Lubartów Plateau (2 objects), Nałęczów Table land (1 object) and Dobrohusk Depression (1 object). The peatlands represented a fen peat type of similar botanic compositions of sediments, but they differed in the area, peat thickness and drain age conditions. Characteristic regular i ties in CEC variability were noted in the peatlands and there were three types of CEC variability in vertical pro files. Carbonate peats (types 1 and 2) had the high est pH and definitely the high est values of CEC. In vertical pro files, there was also a zonation, but the regularities similar to non-carbonate peats were not observed. Different distribution of phys i cal and chem i cal parameters were establishedin vertical pro files in partly drained peatlands (with a muck layer on top) with non-carbonate peats (type 3) and there were three distinct zones in vertical pro files, with different Ac and CEC. Determination of the vertical CEC variability and other phys i cal and chem i cal parameters in peatlands made it possible to distinguish zones with potentially most beneficial isolation conditions.