Effect of wind damage to tree stands on spatial differences in water chemistry in the Kokieliski Stream catchment in the Tatra National Park

The study focused on the effects of deforestation by heavy winds and tree stand damage produced by bark beetle invasion on water chemistry of mountainous catchment of Koscieliski Stream in the Tatra National Park (southern Poland). 200 samples of stream and spring water were collected in three series: in July, August and October 2015. Water samples obtained from areas characterized by tree stand damage caused by heavy winds were found to have much higher mean concentration of nitrate (15.44 mg/L) as well as a much higher overall mean nitrate content (3.44% mval/L) than samples obtained from non-deforested areas (3.26 mg/L and 0.78% mval/L). The increase in nitrate concentration and its share in overall water chemistry was high enough that the anion sequence for the deforested areas became altered from HCO3>SO4>NO3>Cl to HCO3>NO3>SO4>Cl. The mean change in water nitrate concentration in areas with tree stands damaged by the bark beetle was smaller (6.17 mg/L; 1.60% mval/L) than that for areas deforested by wind. The concentration of NO3 in stream water in deforested areas varied more than that in stream water in non-deforested areas.