A climate controlled, dynamic chamber was used to measure carbon dioxide (CO$ sb2$) and methane (CH$ sb4$) exchange on an ombrotrophic peatland. The study periods were July to early November 1995, and early May to July 1996. Five sample sites, showing ecological and hydrological contrast, were investigated. Measurements of Net Ecosystem Exchange showed peak photosynthetic capacity (GP$ sb{ max})$ ranging from 0.52 $ pm$ 0.04 mg C m$ sp{-2}$ s$ sp{-1}$ (June 1996) to 0.03 $ pm$ 0.02 mg C m$ sp{-2}$ s$ sp{-1}$ (early November 1995). Dark respiration measurements ranged from $-$0.21 $ pm$.02 mg C m$ sp{-2}$ s$ sp{-1}$ (June 1996) to $-$0.02 $ pm$.01 mg C m$ sp{-2}$ s$ sp{-1}$ (late May 1996), and showed significant relationships to soil temperature at all sites. Site average methane measurements ranged from 29-72 mg m$ sp{-2}$ d$ sp{-1}$, and showed a strong relationship to water table on a seasonal basis, but a poor correlation to simultaneous NEE. Modelled Net Ecosystem Productivity (NEP) among sites ranged from 17.1 to 115 gC over the entire study period. The CO$ sb2$ exchanges in late spring and early fall made a large contribution to the figure due to the imbalance in the photosynthetic and dark respiration components of the carbon budget. No discernible relationship was found between seasonal NEP and methane release. The results suggest a large importance of the extreme ends of the growing season in an analysis of the carbon budget of peatlands, periods hitherto little investigated. They also suggest that NEP/methane connections may be restricted in their significance to mainly flooded mires.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27274 |
| Date | January 1996 |
| Creators | Ball, Tom. |
| Contributors | Moore, T. R. (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 Geography.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001562235, proquestno: MQ29648, Theses scanned by UMI/ProQuest. |
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