Long-term temporal changes of precipitation quality in slovak mountain forests

Abstract

The paper is focused on the evaluation of long-term changes in the chemical composition of precipitation in the mountain forests of Slovakia. Two stations with long-term measurements of precipitation quality were selected, namely the station of the EMEP (European Monitoring and Evaluation Programme) network Chopok (2008 m a.s.l.) and the station of the ICP Forests (International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests) network Poľana-Hukavský grúň (850 m a.s.l.). All basic chemical components were analyzed, namely sulfur (S-SO4), nitrogen (N-NH4, N-NO3), and base cations (Ca, Mg, and K) contained in precipitation. The time changes of the individual components were statistically evaluated by the Mann–Kendall test and Kruskal–Wallis test. The results showed significant declining trends for almost all components, which can significantly affect element cycles in mountain forest ecosystems. The evaluated forty one-year period (1987 to 2018) is characterized by significant changes in the precipitation regime in Slovakia and the obtained results indicate possible directions in which the quantity and quality of precipitation in the mountainous areas of Slovakia will develop with ongoing climate change.