In the soil, mercury species are predominantly associated with particulate organic carbon (POC) and can be exported with surface runoff by erosion or in solution, associated with dissolved organic carbon (DOC). / Water column samples collected in September 1997 and May 1998 from three treatment groups of lakes (9 whose watershed was clear-cut, 9 whose watershed was burnt, and 20 control lakes, whose watershed forests have not been touched by forest fires or clear-cutting for at least 70 years) were analyzed. Results of these analyses reveal a significant increase in the DOC and dissolved methylmercury concentrations in lake water after watershed clear-cutting. Following forest fires, there is an enrichment of methylmercury in the suspended particulate matter (SPM), as well as significant losses of nitrogen species. Thus, watershed perturbations increase the export of mercury species from the catchment to drainage lakes, and this effect is greater in logged- than in burnt-watershed lakes. This mercury export is dependent on the delivery of POC and DOC to the lakes, which increases as a result of surface runoff intensification. (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.30726 |
| Date | January 2000 |
| Creators | Pinheiro, Fabiola M. R. |
| Contributors | Mucci, Alfonso (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Earth and Planetary Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001746359, proquestno: MQ64431, Theses scanned by UMI/ProQuest. |
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