Chemical characteristics and acid sensitivity of boreal headwater lakes in northwest Saskatchewan

摘要: Boreal ecosystems in northwest Saskatchewan may be threatened by acidification as this area is downwind of atmospheric emissions sources from regional oil sands mining operations. To evaluate the status lakes region, a survey 259 headwater was conducted during 2007–2008 within ~300 km Fort McMurray, Alberta. Acid sensitivity ecoregion increased Mid-Boreal Upland to Churchill River Athabasca Plain, with 60% classified sensitive (50–200 μeq L–1 acid neutralizing capacity (ANC)), and 8% very (<50 ANC) deposition. Organic anions dominated acidity balance most lakes, but non-marine sulphate varied positively lake elevation % upland cover (r2 = 0.24). Base cation concentrations (Ca, Mg, K, Na) were correlated deciduous forest catchment 0.33), while dissolved organic carbon (DOC) related strongly bog flushing variables 0.53). Variation runoff coefficients derived isotope mass corresponded attributes that proxy controls on evaporation, infiltration storage, showed some ecoregional differences. The findings have implications for assignment values required calculate critical loads acidity. Although appears not significantly advanced, many dilute oligotrophic pH 6.0 6.5 are vulnerable