Diverse effects of accelerating climate change on chemical recovery of alpine lakes from acidic deposition in soil-rich versus scree-rich catchments. (1st September 2021)

• Record Type: Journal Article
• Authors: Kopáček, Jiří; Kaňa, Jiří; Porcal, Petr; Stuchlík, Evžen
• Is Part Of: Environmental pollution. Volume 284(2021)
• Publication Date: 2021-09-01
• Subjects: Recovery from acidification -- Water chemistry -- Tatra Mountains -- Long-term trends -- MAGIC modelling; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117522
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The current recovery of mountain lakes from atmospheric acidification is increasingly affected (both accelerated and/or delayed) by climate change. We evaluated long-term trends in the ionic composition of 30 lakes situated in the alpine zone of the Tatra Mountains, and compared the rates of their recovery with model (MAGIC) simulations done 20 years ago for the 2003–2020 period. The observed recovery was faster than the model forecast, due to greater reductions in acidic deposition than projected. Trends in water composition were further modified by climate change. Rising temperatures increased the length of the growing season and retention of inorganic N and SO4 2− more in soil-rich compared with soil-poor catchments. In contrast, elevated precipitation and an increase in rainfall intensity reduced water residence time in soils, and consequently reduced N retention, especially in soil-poor catchments. It is likely that increases in rainfall intensity and annual number of days without snow, along with air temperatures fluctuating around the freezing point elevated the physical erosion of rocks, especially in high-elevation, steep, and scree-rich areas where rocks are not thermally insulated and stabilized by soils. Weathering of exposed accessory calcite in the eroded granodiorite bedrock was a source of Ca 2+ and HCO3 −, while S-bearing minerals likely contributed to lake water SO4 2− and partly mitigated its deposition-related decrease in scree-rich catchments. The extent of climate effects on changes in the water composition of alpine lakes recovering from acidic deposition thus depended on elevation and cover of soil and scree in catchments. Our results highlight the need for incorporating dominant climate-related process into existing process-based models to increase their reliability in predicting the future development of lake water composition. Graphical abstract: Image 1 Highlights: We evaluated the recovery of alpine lakes from acidification in the Tatra Mountains. In addition to decreasing acidic deposition, climate change contributed to recovery. The effect of climate change has accelerated since the middle 2000s. Rock weathering increased and S and N immobilization in catchments changed. The effects of climate change differed along elevation and soil cover gradients. Abstract : Effects of climate change on water composition of alpine lakes recovering from acidification differed along elevation and soil cover gradients of their catchments.