In this research, a recent version of the Boreal Ecosystem Productivity Simulator (BEPS),
called BEPS-TerrainLab, was adapted to northern peatlands and evaluated using observations
made at the Mer Bleue bog located near Ottawa, Ontario, and the Sandhill fen located near
Prince Albert, Saskatchewan. The code was extended and modified with a major focus on the
adequate representation of northern peatlands' multi-layer canopy and the associated processes
related to energy, water vapour and carbon dioxide
fluxes through remotely-sensed leaf area index (LAI) maps. An important prerequisite for the successful mapping of LAI based on remote
sensing imagery is the accurate measurement of LAI in the field with a standard technique such
as the LAI-2000 plant canopy analyzer. As part of this research, a quick and reliable method
to determine shrub LAI with the LAI-2000 instrument was developed. This method was used
to collect a large number of LAI data at the Mer Bleue bog for the development of a new
remote sensing-based methodology using multiple endmember spectral unmixing that allows
for separate tree and shrub LAI mapping in ombrotrophic peatlands. A slight modification of
this methodology allows for its application to minerotrophic peatlands and their surrounding
landscapes. These LAI maps were used to explicitly represent the tree and shrub layers of the
Mer Bleue bog and the tree and shrub/sedge layers of the Sandill fen within BEPS-TerrainLab.
The adapted version of BEPS-TerrainLab was used to investigate the in
fluence of mescoscale
topography (Mer Bleue bog) and macro- and mesoscale topography (Sandhill fen) on wetness,
evapotranspiration, and gross primary productivity during the snow-free period of 2004. This
research suggests that future peatland ecosystem modelling efforts at regional and continental scales should include a peatland type-specific differentiation of macro- and mesoscale topographic effects on hydrology, to allow for a more realistic simulation of peatlands' soil water
balance. This is an important prerequisite for the reduction of currently existing uncertainties
in wetlands' contribution to North America's carbon dioxide and methane annual
fluxes from
an ecosystem modelling perspective.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OTU.1807/11264 |
| Date | 01 August 2008 |
| Creators | Sonnentag, Oliver |
| Contributors | Chen, Jing Ming |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
| Format | 39942707 bytes, application/pdf |
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