Effects of groundwater level fluctuation on its chemical composition in karst soils of Lithuania

Groundwater regime and mineralization process in moraine sandy loam and peat soils of the active sulphatic karst zone (karst processes develop in the Upper Devonian gypsum-dolomites) in Lithuania and the dependence of chemical compounds concentrations on water level fluctuations are reviewed. According to ion sum, groundwater mineralization in peat soil is 1.1-1.3 times higher than in loam soil. Based on this result, lower levels of groundwater predetermine a more intensive mineralization process. A stronger correlation was determined between groundwater levels and concentrations of chemical compounds (Ca2+, Mg2+, SO42- and HCO3-) enhancing groundwater mineralization. In mineral soil (sandy loam) nitrate (NO3)(-) concentration is highly influenced by changing stages of groundwater level as well as by nearby sinkholes.