ACIDIFICATION OF SMALL MOUNTAIN LAKES IN THE HIGH TATRA MOUNTAINS, POLAND

A hydrochemical investigation was carried out on eight small High Tatr a mountain lakes (Poland). When comparing recent data with those from the period 1935-1965, a constant process of acidification of the lakes is found. The average pH of precipitation is 4.8 in the study area, b ut the lakes are in two stages of acidification: weak (pH 6.0-6.5) and intermediate (pH 5.5-5.8). The differences are due to differences in water sources.