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Dissolved nitrogen dynamics in an ombrotrophic bog

Research for a dissolved nitrogen budget was conducted at Mer Bleue bog near Ottawa, ON, from May 20, 2003 to May 21, 2004. Mer Bleue is located within an area experiencing the highest levels of atmospheric nitrogen deposition in North America, although these levels are only low to moderate compared to those in Europe. Continuous measurements of precipitation, evapotranspiration, bog water table level and outflow water depth were used in conjunction with discrete measurements of precipitation and outflow to determine the hydrologic budget. Water samples were taken from precipitation collectors, piezometers at various depths and locations throughout the bog, and an outflow point in order to gauge changes and patterns in chemical concentrations at various points throughout the bog. The nature of the bog morphology and landscape allowed for collection of water samples from a single outflow point. / Chemical analysis combined with the water budget revealed that the majority of the dissolved nitrogen is entering the bog as NO3-N and NH 4-N (inorganic nitrogen), and leaving the bog as dissolved organic nitrogen (DON). Export of nitrogen was generally low relative to the input, and was only a very small fraction of the huge amount of nitrogen stored in the bog. Bog porewater concentrations were dominated by DON and did not show spatial patterns in relation to the bog edge. When comparing the annual accretion of nitrogen at the bog to the long-term storage numbers, it was apparent that there is a missing source of nitrogen. From the literature and patterns in the bog, it appears that this missing input at Mer Bleue is likely due to a combination of previously unmeasured nitrogen fixation and more diverse usage of DON by bog vegetation.

Identiferoai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.98773
Date January 2006
CreatorsRattle, Jean.
PublisherMcGill University
Source SetsLibrary and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada
LanguageEnglish
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Formatapplication/pdf
CoverageMaster of Science (Department of Geography.)
Rights© Jean Rattle, 2006
Relationalephsysno: 002479210, proquestno: AAIMR24774, Theses scanned by UMI/ProQuest.

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