What affects the nitrogen retention in Tatra Mountains lakes' catchments in Poland?

Abstract

Abstract. The study of acidification and recovery of two lakes situated in the Polish Tatra Mountains, exposed to similar deposition of acidic substances but differing in altitude, catchment morphology, hydrology, and biodiversity is presented. Measurements were performed in 1992-1996 and 2001-2005. Simultaneously, research on the atmospheric deposition was carried out. The following physical and chemical parameters in lake water and precipitation were measured: pH, conductivity (K 25 ), Ca 2+ , Mg 2+ , Na + , K + , NH (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005). During this time the sulphate concentration decreased significantly, and the concentration of hydrogen ions in precipitation decreased at an average rate of 2.23 meq/m 3 /yr. There was no significant change in nitrate, ammonium or total nitrogen deposition. The chemical composition of water of both lakes changed significantly and showed signs of chemical recovery with decreases in sulphate concentration and increases in acid neutralising capacity. The concentration of base cations declined. Despite the lack of clear trends in nitrogen deposition, a statistically significant drop in concentration was observed in the two lakes. A significant increase of about 15% in the retention of nitrogen compounds in both catchments occurred. An improvement in nitrogen saturation status in both catchments was observed. This probably resulted mainly from decreasing acidification and global warming which prolongs the vegetative period, changes plant species composition and increases the microbiological activity of soil.

Ecological dynamics of two remote alpine lakes during ice-free season

“…Indeed, the areas surrounding the Alpine rim produce nitrogen deposition among the highest in Europe (Rogora et al, 2001) and, in 2009, the total N concentration (0.88 mg L -1 ) and deposition rates (14.4 kg N ha -1 y -1 , calculated by annual precipitation and average N content) at the sampling station of La Thuile were high and similar to those usually reported for the Alpine range (N deposition rate: 14-15 kg N ha -1 y -1 ; Rogora et al, 2006). However, the final nitrogen concentration in the lakes depends on retention process (closely related to vegetation and catchment characteristics) (Marchetto et al, 1995;Rzychon and Worsztynowicz, 2008), in addition to N deposition rate. Inorganic nitrogen concentration in the lakes studied (0.07 mg N L -1 in NIV, and 0.04 mg N L -1 in TRS) was considerably lower than the values found in other lakes in the Gran Paradiso National Park (0.17 mg L -1 , average IN concentration from a set of 15 Alpine lakes sampled in 2009, unpublished data) and for the Alps (0.8-1.0 mg L -1 ) (Rogora et al, 2003(Rogora et al, , 2008, and it was comparable with the values from European and non-European pristine areas subject to low atmospheric input of N compounds (Boavida and Gliwicz, 1996;Tartari et al, 1998;Murphy et al, 2010).…”

Geomorphology and hydrochemistry of 12 Alpine lakes in the Gran Paradiso National Park, Italy

“…Finally, the 12 Gran Paradiso studied lakes seem to be well preserved by acidification risk and this works in advantage of researchers who aim to stand out other chemical or ecological dynamics and local or global impacts; as a matter of facts acidification and other environmental threats will interact according to complex and site specific way (Wright & Schindler 1995;Schindler et al 1996;Yan et al 1996;Sommaruga-Wograth et al 1997) generating additional complexity. In spite of this, little can be said about long range pollutants as heavy metals and POPs: the relative low detected TN concentration is not necessarily a synonym of a soft impact of long range pollutants, being the final nitrogen concentration dependent from retention process (closely related to catchment characteristics) (Rzychon & Worsztynowicz 2008) besides N deposition rates; moreover the dominance of IN on ON highlight that the lakes are interested by N deposition and probably by long range transport of pollutants produced in the urbanized area surrounding the massif.…”

Linking Snow, Soil, and Stream During Snowmelt and Rain‐On‐Snow Events: Storage and Transport of Ions in an Acid‐Sensitive Alpine Catchment (Tatra Mountains, Poland)

“…This particular problem intensified in the second half of the 20th century along with the development of heavy industry and an increase in the emissions of acid‐forming gases into the Earth's atmosphere, such as nitrogen oxide and sulfur oxide (Schöpp et al., 2003). Acidic atmospheric precipitation in the 1960s and 1970s caused a large decrease in the pH of surface water (Borg & Sundbom, 2014; Likens et al., 1996; Ryan et al., 1989; Rzychoń & Worsztynowicz, 2008; Wigington et al., 1992). A particularly large decrease in the pH of river water was observed during snowmelt events (Denning et al., 1991; Rascher et al., 1987).…”