Environmental Science and Pollution Research

, Volume 19, Issue 2, pp 361–371

Increases of dissolved organic carbon in temperate and boreal lakes in Quebec, Canada

Research Article

DOI: 10.1007/s11356-011-0565-6

Cite this article as:
Couture, S., Houle, D. & Gagnon, C. Environ Sci Pollut Res (2012) 19: 361. doi:10.1007/s11356-011-0565-6

Abstract

Purpose

Increases in dissolved organic carbon (DOC) concentrations have been reported in surface waters worldwide in the last 10 to 20 years. The causes behind these increases have been attributed to many factors, including climate change and decreasing depositions of atmospheric sulphate (\( {\text{SO}}_4^{{{2} - }} \)). Trends in DOC concentrations and their potential causal factors were examined in a network of 30 lakes lying in undisturbed temperate and boreal catchments in the province of Quebec, Canada.

Methods

Temporal trends in lake DOC concentrations were analysed with the seasonal Kendall test. For each lake, the variation in DOC concentration over time was assessed in light of the variation in \( {\text{SO}}_4^{{2 - }} \) concentration in precipitation, air temperature, precipitation and solar radiation using the forward stepwise multiple regression.

Results

Between 1989 and 2006, significant increases in DOC were observed in most of the lakes, the mean rate of change being 0.05 mg L−1 year−1. Lake DOC concentrations were significantly explained by different models that yielded a variance explanation ranging from 13% to 77%. The models included long-term temperature variables (i.e. averaged over intervals of 10 years), short-term precipitation variables (i.e. summed over intervals 6 months), radiation (i.e. ice-free period prior to the DOC observation) and precipitation \( {\text{SO}}_4^{{2 - }} \) concentration as explanatory variables.

Conclusion

Temporal changes in DOC concentrations seem more consistent with the evolution of climate parameters rather than \( {\text{SO}}_4^{{2 - }} \) concentrations despite the fact that most lakes were in the process of recovery, showing increases in pH.

Keywords

Dissolved organic carbonClimateSulphate depositionLakesQuebec Canada

Copyright information

© © Her Majesty the Queen in Right of Canada 2011

Authors and Affiliations

  • Suzanne Couture
    • 1
  • Daniel Houle
    • 1
    • 2
  • Christian Gagnon
    • 1
  1. 1.Environment Canada, Science and Technology BranchMontrealCanada
  2. 2.Ministère des Ressources Naturelles du Québec, Direction de la Recherche ForestièreSainte-FoyCanada