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Northern peatlands are globally significant carbon sinks; however, this function can be lostthrough peatland disturbance. Commercial peat extraction involves vegetation clearing andpeatland drainage, resulting in mineralization of stored organic matter and large carbondioxide (CO2) emissions. Following peat extraction, ecosystem recovery is oftenpoor without active rewetting or restoration actions. Over 25 years of research inCanada has led to the development of the moss layer transfer technique (MLTT) forpeatland restoration, that can efficiently establish plant communities dominated bypeatland and wetland species and return carbon accumulation function within decades.However, the trajectory of C fluxes with time post-restoration remains unclear, asdoes the variation in this trajectory between the plant communities that establishpost-restoration. We compiled CO2 and methane emission data from different ages of restored Canadianpeatlands collected with manual chamber measurements and eddy covariance methods anddetermined the shift in annual C exchange over time. As these measurements were limitedto less than five sites and vegetation establishment can vary greatly within andbetween restoration projects, we explored this variation by collecting over 500samples representing of all aboveground biomass accumulated since restoration acrosspermanent plots established in restored peatlands ranging in age from 2-20 yearspost-restoration and varying in vegetation outcomes. For ∼50 plots, we sorted allbiomass into plant tissue types (wood, shrub leaves, herbs, bryophytes, litter) andcalculated average net primary productivity considering the turnover rates of each tissuetype. Flux data indicates that peatlands restored via MLTT are originally large sources ofcarbon (∼600 g C m−2 yr−1), but this source rapidly declines over time as vegetationestablishes. Measurements at one site indicate that a C sink function can be achieved by 15years post-restoration (uptake of ∼80 g C m−2 yr−1). Total biomass increasedsignificantly over time, varying between vegetation outcomes. Calculated net primaryproductivity increased over time, but stabilized at older sites as biomass accumulatedin early years was beginning to decompose. Future work will target carbon fluxmeasurements on specific vegetation outcomes of various ages to determine emissionfactors that can be applied across mapped post-restoration vegetation establishment. [ABSTRACT FROM AUTHOR]

Peatlands play a significant role in global greenhouse gas (GHG) cycling as they store a significant amount (approx. 550 Gt) of organic carbon in the form of peat. The boreal region of Canada has one of the highest densities of peatlands. However, they have been impacted by various linear disturbances including winter roads, pipelines, seismic lines, oil sand drillings (well-pads), and resource access road construction. A more than 217,000 km long road network has been constructed on the boreal region of Canada to explore and extract natural resources (e.g. oil sands and forestry). Roads on peatlands are raised by placing mineral fill on the compressed peat underneath. Therefore, the road itself acts as a dam and limits the hydrological connection between fragmented parts of the peatland. The resulting hydrological variation may lead to altered GHG emissions, plant community, microbial activity, and soil biogeochemistry in peatlands. However, few studies have quantified the impacts of access roads on boreal peatland carbon dynamics. Therefore, we conducted a study focusing on the impacts of roads on carbon dynamics of a forested bog and a shrubby fen near Peace River, Alberta, Canada. Data was collected in 2016 and 2017 from May to August. The data plots represented three factors: 1) side of the road (upstream and downstream), 2) distance from a culvert (<2 and >20 m), and 3) and distance from either side of the road (2, 6, 20 m). Results from 2016 showed that, overall, the ground layer of the bog was a source (1.66 g CO2 m-2 d-1) and the fen was a sink (-19.06 g CO2 m-2 d-1) of CO2. In 2017, the ground layers of both the bog and fen were sinks of CO2 (-1.35 g CO2 m-2 d-1 and -19.06 g CO2 m-2 d-1, respectively). In general, hydrologic effects of the road were less at the fen due to the orientation of the road relative to the local slope of the peatland. At this site, variation in C fluxes relative the road was also small, but there was an overall reduction in C sink function due to plant community disturbance. At the bog, flooding occurred on the upstream side of the road. This was more severe far from culverts and close to the road. When culverts were in place, water was moved across the road, but wet conditions were created on the downstream side due to concentration flow. This resulted in higher CH4 emissions close to the road and reduced CO2 uptake so that the area near the road had a greatly reduced C and GHG sink function than undisturbed areas, even when culverts were present.However, the carbon flux varied depending on the side of the road, distance from the road, and the distance from the culvert. In our presentation, we will present the main findings of our study and show how resource roads have the potential to alter the carbon dynamics of peatlands. Also, we will recommend measures how the road associated impacts could be minimized. [ABSTRACT FROM AUTHOR]