%0 Research Notes %T Seasonal changes in water chemistry in a bog on the Southern Alps %A Bragazza, Luca %D 1993 %J Suo - Mires and peat %V 44 %N 4-5 %U http://suo.fi/article/9732 %X Concentrations of sodium, potassium, calcium and magnesium were periodically measured in precipitation and in pool water in a bog on the Southern Alps during the 1991 vegetative season. A simple model was established for calculating theoretical concentrations of those cations in bog water, taking into account the effect of potential evapotranspiration. The actual concentrations of cations in bog water were then compared with the theoretical ones and this allowed to define different seasonal patterns of cation concentrations. Sodium accumulated in bog water with respect to precipitation, to an extent far exceeding the enrichment due to evaporation. A possible explanation of this resides in a surface enrichment owing to capillary flow. Potassium, and to a lesser extent magnesium, accumulated in spring and autumn but were actively removed by plants in summer. Calcium was removed also outside the growing season, probably by cation exchange on peat. Keywords: bog water, cations, evapotranspiration, precipitation, seasonal variation.