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4635082 
Journal Article 
Comparative impacts of fire and forest harvesting on water quality in Boreal Shield lakes 
Carignan, R; D'Arcy, P; Lamontagne, S 
2000 
Yes 
Canadian Journal of Fisheries and Aquatic Sciences
ISSN: 0706-652X
EISSN: 1205-7533 
57 (0 
S2 
105-117 
Water quality was monitored in Boreal Shield lakes for 3 years following their simultaneous impact by clearcut logging or wildfire. Seventeen similar undisturbed lakes served as references. Dissolved organic carbon (DOC) and the light attenuation coefficient ( epsilon sub(PAR)) were up to threefold higher in cut lakes than in reference and burnt lakes. Compared with median values for reference lakes, cut and burnt lakes had higher concentrations of total phosphorus (TP) (two- to three-fold), total organic nitrogen (TON) (twofold), and K super(+), Cl super(-), and Ca super(2+) (up to sixfold). NO super(-) sub(3) and SO super(2) sub(4) super(-) concentrations were up to 60- and 6-fold higher, respectively, in burnt lakes than in reference and cut lakes. In most cases, impacts were directly proportional to the area harvested or burnt divided by the lake's volume or area. These simple models correctly predicted the changes observed in three lakes harvested during the study. Some of the ob served effects occur on different time scales. Mobile ions released by fire (K super(+), Cl super(-), SO super(2) sub(4) super(-), NO super(-) sub(3)) or harvesting (K super(+), Cl super(-), some DOC) are rapidly flushed out of the watershed (50% decrease in 3 years). Other constituents or properties (TP, TON, DOC, epsilon sub(PAR), Ca super(2+), Mg super(2+)) show little change or are still increasing after 3 years and will take a longer time to reach normal levels. 
Fires; Lakes; Forests; Water quality; Harvesting; Water quality measurements; Dissolved organic carbon; Nutrient concentrations; Forestry; Organic carbon; logging; Nutrients; Forest cutting; Water quality (Natural waters); Deforestation; Environmental Effects; Clear-cutting; Forest Fires; wildfire; Canada; clear cutting; Canada, Boreal Shield; 2000)