Low methane emissions from a boreal wetland constructed on oil sand mine tailings
<p>A 58 ha mixed upland and lowland boreal plains watershed called the Sandhill Fen Watershed was constructed between 2008 and 2012. In the years following wetting in 2013, methane emissions were measured using manual chambers. The presence of vegetation with aerenchymous tissues an...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-02-01
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| Series: | Biogeosciences |
| Online Access: | https://www.biogeosciences.net/17/667/2020/bg-17-667-2020.pdf |
| Summary: | <p>A 58 ha mixed upland and lowland boreal plains
watershed called the Sandhill Fen Watershed was constructed between 2008 and
2012. In the years following wetting in 2013, methane emissions were
measured using manual chambers. The presence of vegetation with aerenchymous
tissues and saturated soils were important factors influencing the spatial
variability of methane emissions across the constructed watershed.
Nevertheless, median methane emissions were equal to or less than 0.51 mg <span class="inline-formula">CH<sub>4</sub></span> m<span class="inline-formula"><sup>−2</sup></span> h<span class="inline-formula"><sup>−1</sup></span> even from the saturated organic soils in the
lowlands. Although overall methane emissions remained low, observations of
methane ebullition increased over the 3 study years. Ebullition events
occurred in 10 % of measurements in 2013, increasing to 21 % and 27 % of measurements in 2014 and 2015, respectively, at the plots with
saturated soils. Increasing metal ion availability and decreasing sulfur
availability was measured using buried ion exchange resins at both seasonal
and annual timescales potentially as a result of microbial reduction of
these ions. Using principle component analysis, methane fluxes had a
significant positive correlation to the leading principle component which
was associated with increasing ammonium, iron, and manganese and decreasing
sulfur availability (<span class="inline-formula"><i>r</i>=0.31</span>, <span class="inline-formula"><i>p</i><0.001</span>). These results suggest
that an abundance of alternative inorganic electron acceptors may be
limiting methanogenesis at this time.</p> |
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| ISSN: | 1726-4170 1726-4189 |