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http://hdl.handle.net/11375/25114
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DC Field | Value | Language |
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dc.contributor.advisor | Waddington, James Michael | - |
dc.contributor.author | Wilkinson, Sophie | - |
dc.date.accessioned | 2019-12-19T13:55:34Z | - |
dc.date.available | 2019-12-19T13:55:34Z | - |
dc.date.issued | 2019 | - |
dc.identifier.uri | http://hdl.handle.net/11375/25114 | - |
dc.description.abstract | Northern peatlands represent a globally significant carbon stock, equating to almost one-third of the world’s organic soil carbon. The largest areal disturbance to northern peatlands is wildfire where carbon loss, through peat smouldering combustion, is highly variable. The tightly-coupled ecohydrological nature of peatlands results in autogenic feedbacks and the occurrence of threshold behaviour. High depth of burn has been evidenced in black spruce dominated peatlands in the sub-humid Boreal Plains ecozone of Alberta, Canada so this was chosen as the area of study. A landscape-scale assessment of peat hydrophysical properties found that peat smouldering combustion vulnerability was greatest at stand-age > 80 years, in coarse/heterogeneous hydrogeological settings, and in peatland margins compared to peatland middles. In combination, and when exposed to a climatic water deficit, we found that these drivers of cross-scale variability could lead to high peat burn severity. Assessment of a partially-drained and burned peatland enabled the identification of a black spruce basal diameter threshold that corresponded to the occurrence of high peat burn severity. We suggest that the above-ground fuel load threshold could occur due to the initiation of a self-reinforcing feedback by anthropogenic disturbance or climate change. Moreover, surpassing a peat burn severity threshold can cause the breakdown of an important feedback that limits evaporation losses post-fire, likely leading to further carbon losses through increased decomposition rates and/or ecosystem regime shift. We found that although peat moisture content was increased by fuel modification treatment, combustion carbon losses were greater in fuel-treated areas compared to the control because of the addition of mulch (wood) to the surface. Hence, peatland wildfire management that integrates the modification of above- and below-ground fuels, considers ecohydrological thresholds, and drivers of cross scale variability, is required to effectively reduce the risk of high peat burn severity in black spruce dominated peatlands. | en_US |
dc.language.iso | en | en_US |
dc.subject | Wildfire | en_US |
dc.subject | Peat | en_US |
dc.subject | Carbon | en_US |
dc.subject | Hydrology | en_US |
dc.subject | Peatland | en_US |
dc.subject | Climate Change | en_US |
dc.title | Ecohydrological Thresholds to High Peat Burn Severity: Implications for Peatland Wildfire Management | en_US |
dc.title.alternative | Ecohydrological Thresholds to High Peat Burn Severity | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | Earth and Environmental Sciences | en_US |
dc.description.degreetype | Thesis | en_US |
dc.description.degree | Doctor of Philosophy (PhD) | en_US |
Appears in Collections: | Open Access Dissertations and Theses |
Files in This Item:
File | Description | Size | Format | |
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Wilkinson_Sophie_L_finalsubmission201912_PhD.pdf | 2.89 MB | Adobe PDF | View/Open |
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