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Recent research into the production of Sphagnum biomass in extracted peatlands, an alternative to ecological restoration as a post-industrial use of peatlands, has highlighted the need for an improved understanding of the ecohydrology of Sphagnum regenerating in these environments. Previous work suggested that limited connectivity between surficial layers and the underlying partially decomposed plant matter and peat would result in water stress and inhibited growth. This study links the soil water dynamics of regenerated layers ranging in age from 3 to 43 years and from 3 to 40 cm in thickness to the productivity of Sphagnum in order to determine the hydrological controls on productivity and the optimal range of water content for producing Sphagnum biomass. Productivity was never observed to be limited by insufficient supply of water, including during periods where water table was >40 cm below the surface and periods of 16 days without measured precipitation. While layers of different ages and thicknesses were able to sustain adequate water supply to remain productive under a range of conditions, the ability of layers to transmit water upwards differed greatly. Water content in the near-surface inhibited productivity during wetter periods, especially at newly regenerating sites where the layer was <5 cm thick. This has important implications for biomass production using the Sphagnum species studied here. Using a mixed linear modelling approach to isolate the effects of water content on variance in productivity from those of other measured variables, a volumetric water content of 0.10 is identified as optimal. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Wetlands are found extensively throughout the Western Boreal Plain, a region under pressure because of disturbance by the oil and gas industries. To understand how wetland systems may respond to disturbance and set targets for reclamation efforts, it is necessary to understand natural variability in nutrient dynamics in the landscape. The purpose of this study was to characterize spatial variability in peatland nutrient (nitrogen, N, and phosphorus, P) dynamics in the Athabasca Oil Sands (AOS) region. N and P availability and net mineralization rates in the upper 10 cm layer of peat were examined during the peak growing season in five peatlands that fell along an apparent moisture gradient. N and P dynamics within and among the sites were related to water table position, peat moisture content and temperature. Phosphorus supply rates and total inorganic N pools and supply rates were generally elevated under wetter conditions, whereas nitrate (NO3−) pools and supply rates and P pools did not vary along a moisture gradient. In general, net immobilization was observed at the wetter sites where nutrient pools were elevated and net mineralization was observed at drier sites where nutrient pools were lower. Nutrient transformation rates were most strongly driven by warmer temperatures. Nutrient availability and immobilization rates were anomalously high at one peatland (a disturbed fen with a semi-permanent road and decommissioned well pads). We suggest that reclamation and management practices should focus on regulating peatland hydrologic conditions, optimizing these for the most desirable nutrient levels for vegetation growth. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Within peatland ecosystems, small deviations in surface elevation result in microforms that differ in depth to water table, plant type and rate of biogeochemical cycling, possibly leading to differences in peat physical and hydrological properties that could feed back to the whole ecosystem hydrological and biogeochemical function. However, hydrological parameters for peatland microforms have not been quantified. This study determined bulk density, pore size distribution and saturated hydraulic conductivity (Ksat) at hummocks and hollows of four, Sphagnum-dominated Canadian peatlands. Study sites included both a bog and poor fen in each of Alberta and Quebec allowing for investigation of differences in peat hydrophysical properties between microforms across a range of Sphagnum-dominated peatlands. Hydraulic conductivity was determined in the laboratory on peat from the surface (0.03-0.08 m) and the saturated zone (0.20 m below the local water table position). Peatland type, climate region, microform and depth of peat were all significant descriptors of variation in Ksat. Deeper peat was less conductive than surface peat. Hummocks generally had higher Ksat than hollows at both surface and saturated zones, although differences between microforms varied between sites. Differences in Ksat between samples were correlated with bulk density, von Post humification and macroporosity. These results indicate that there are microtopographical differences in peat hydrophysical properties; however, the strong decline in Ksat with depth indicates that differences in the local water table, resulting in a change in depth of water flow, is likely a stronger control on local Ksat than microform type. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Recently, methanotrophic members of the phylum V errucomicrobia have been described, but little is known about their distribution in nature. We surveyed methanotrophic bacteria in geothermal springs and acidic wetlands via pyrosequencing of 16 S rRNA gene amplicons. Putative methanotrophic V errucomicrobia were found in samples covering a broad temperature range (22.5-81.6° C), but only in acidic conditions ( pH 1.8-5.0) and only in geothermal environments, not in acidic bogs or fens. Phylogenetically, three 16 S rRNA gene sequence clusters of putative methanotrophic V errucomicrobia were observed. Those detected in high-temperature geothermal samples (44.1-81.6° C) grouped with known thermoacidiphilic ' M ethylacidiphilum' isolates. A second group dominated in moderate-temperature geothermal samples (22.5-40.1° C) and a representative mesophilic methanotroph from this group was isolated (strain LP2 A). Genome sequencing verified that strain LP2 A possessed particulate methane monooxygenase, but its 16 S rRNA gene sequence identity to ' M ethylacidiphilum infernorum' strain V4 was only 90.6%. A third group clustered distantly with known methanotrophic V errucomicrobia. Using pmoA-gene targeted quantitative polymerase chain reaction, two geothermal soil profiles showed a dominance of LP2 A-like pmoA sequences in the cooler surface layers and ' M ethylacidiphilum'-like pmoA sequences in deeper, hotter layers. Based on these results, there appears to be a thermophilic group and a mesophilic group of methanotrophic V errucomicrobia. However, both were detected only in acidic geothermal environments. [ABSTRACT FROM AUTHOR]

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]

Restoration of extracted horticultural peatlands commonly includes distribution of vegetation and propagules from nearby undisturbed sites over the recently-exposed surface. The resulting growth includes both mosses and vascular plants, which are important contributors to returning a peatland to a net carbon-storing ecosystem. Nitrous oxide (N 2 O) flux has not been widely investigated in these restored ecosystems. We compared the N 2 O flux from plots containing a vascular plant, Eriophorum vaginatum, to plots lacking vascular plant cover at a recently restored peatland. We hypothesized that E. vaginatum would result in decreased N 2 O emissions compared to areas with only moss or bare peat due to rapid plant uptake of peat nitrogen. After an early-summer pulse of emitted N 2 O, study plots containing E. vaginatum transitioned to net consumers of N 2 O while bare plots remained sources as the summer progressed. Furthermore, E. vaginatum growing in the wettest parts of the study site also had significantly more extractable nitrogen in pore water collected from 75 cm below the surface, beyond the depth of most roots. We suggest the priming effect driven by the roots of this vascular plant, combined with high water levels, frees some nitrogen from previously-inaccessible recalcitrant organic matter that then is taken up by plant roots and/or soil microorganisms, preventing its release as N 2 O. Vascular plants may play important roles in both greenhouse gas processes and in the nutrient cycles of restored peatlands and these complex processes need further investigation to guide effective restoration efforts that aim to return these disturbed ecosystems to net greenhouse gas sinks. [ABSTRACT FROM AUTHOR]

Seismic lines are prominent linear disturbances across boreal Canada with large-scale consequences to wildlife and ecosystem function. Although seismic line restoration has been observed to improve tree growth and survival, application in peatlands has been shown to alter ecosystem functions such as hydrology and carbon storage. The most common active restoration method is called mechanical mounding, where the classic technique inverts the peat profile. New mounding methods that maintain the peat profile may provide benefits by preserving existing vegetation and reducing disturbance. To determine the effects of different mounding methods on soil quality, we collected and analyzed peat cores from two different sites for various soil properties (C/N ratios, δ13C, δ15N, and Fourier transform infrared (FTIR) spectroscopy humification indices). Vegetation surveys were also conducted. The two sites are both a collection of seismic lines crossing poor fens in Alberta. One site was treated with the classic method, while the other was treated with two new mounding methods. Classic mechanical mounding significantly increased the degree of decomposition, indicative of lower substrate quality. Mechanical mounding also greatly reduced moss cover and introduced large amounts of bare ground cover. The two newer mounding methods did not result in these changes and were largely comparable to natural peat properties and vegetation communities. Preserving the peat profile in new mounding methods may support faster return of ecosystem function. [ABSTRACT FROM AUTHOR]

Aims: This study assesses the relative effects of hydrology and colonization by vascular plants on belowground C and N mobilization, and emission of CO2 and CH4 in an extracted bog under restoration in Alberta (Canada). Methods: A wet (high water table) and dry (low water table) area were identified at the site and plots with cottongrass (Eriophorum vaginatum) or bare peat were established in each area. Plant growth, peat and porewater dissolved C (DOC) and N (TDN), microbial biomass and the emissions of CO2 and CH4 were monitored at the plots throughout the growing season. Results: The largest concentrations of DOC were measured in dry and bare sites. Lower E2:E3 ratios suggested a higher aromaticity of the DOC at these sites that were net sources of CO2 and CH4. The concentration of TDN was greater in plots with cottongrass and high water table, supporting a more abundant microbial biomass. Cottongrass dominated plots also had larger gas emissions as compared to bare plots even though they were net C sinks due to their high photosynthetic rates. Conclusion: Maintaining a high water table is key to reducing peatland C losses. While vascular plant presence seems to prime the release of N and greenhouse gases, the inputs of C exceeded the losses and recovered the C sink function of the peatland ecosystem in the short term. Carbon inputs are maximized under high water table and plant presence. [ABSTRACT FROM AUTHOR]

• DOC concentrations have continued to increase since fen construction. • DOC present within the fen is likely more recently produced and plant-sourced. • Input from the surrounding hillslopes had minimal impact on the quality of the DOC. • DOC export from the fen itself was low. • Necessary to continue DOC monitoring to understand changes under future climatic variations. Vast areas of wetlands in the Athabasca Oil Sands Region, Alberta, Canada have been disturbed for mining and other resource extraction activities. In recent years, these disturbed areas have become a focus for reclamation activities. To improve our understanding of the biogeochemical cycling of constructed ecosystems, it is important that we study the production of, as well as the inputs and outputs of dissolved organic carbon (DOC) in the system. The aim of our study was to investigate the hydrological DOC fluxes into a constructed fen in 2015 and 2016 (2- and 3-years post-construction respectively), relative to internal DOC production, and to assess the potential importance of each source for DOC export using DOC concentration and quality parameters. Our results show that while runoff added a small amount of DOC in both years, DOC concentration within the fen is driven largely by increased vegetation production, with DOC increasing in the years since construction. The measured quality indices (SUVA 254 , E2/E3, FI, HIX, and β/a) all showed that DOC present in the system is likely more recently produced and plant sourced. There was also little evidence that precipitation and runoff inputs from hillslopes impacted the quality of DOC present in the fen, while DOC export from the fen was minimal. As this constructed wetland continues to mature, it is important that monitoring of DOC continues in order to understand the trajectory of biogeochemical dynamics of the system following vegetation establishment, as well as changes under potential future climatic variations. [ABSTRACT FROM AUTHOR]

• Roads obstruct surface and sub-surface water flow in peatlands. • Road orientation perpendicular to water flow resulted in upstream flooding in bog. • Road orientation parallel to the water flow minimized hydrological impacts in fen. • Adequate culvert placement connects water flow across road. Resource-access road crossings are expected to alter peatland hydrological properties by obstructing surface and sub-surface water flows. We conducted a multi-year study at two boreal peatlands – a forested bog and a shrubby rich fen near Peace River, Alberta – to study the impacts of resource access roads on the hydrology of adjacent peatland. Field measurements (bi-weekly depth to water table and hydraulic head, one-time hydraulic conductivity) during the growing seasons (May-August) of 2016 and 2017 were taken from sampling plots representing: 1) sides of the road (upstream and downstream); 2) distance from the road (obstruction); and 3) distance from culverts. Compared to the growing season average precipitation for the region of 1.8 mm d−1, the study period had very wet conditions in 2016 (3.7 mm d−1) and dry conditions in 2017 (1.1 mm d−1). In contrast to our assumptions, resource access road disturbed the surface and sub-surface water flow at the bog, but the effect was minimal at the fen as the road orientation was nearly parallel to the flow direction at the latter. At the bog, the shallowest depth to water table position was observed at upstream areas closer to the road, when culverts were located >20 m distance from transects. In contrast, when culverts were present <2 m from the transects, variation in hydrological conditions between upstream and downstream areas were greatly reduced. Our work shows road effects on peatland hydrology could be minimized by aligning roads parallel to the water flow direction when possible. If water flow is perpendicular to the road, adequate spacing and installation of culverts could help to reduce flow obstruction. [ABSTRACT FROM AUTHOR]

The moss layer transfer technique has been developed to restore the carbon sequestration function and typical vegetation of Sphagnum-dominated peatlands after peat extraction in North America. However, the technique does not lead to successful bryophyte establishment when applied to peatlands with a richer residual fen peat. Therefore, we evaluated an alternative method of active rewetting and passive vegetation establishment using vegetation surveys and carbon dioxide and methane (CH 4 ) flux measurements at a post-extracted fen in southern Manitoba, Canada. After one growing season post-rewetting, wetland vegetation established and the site was a net carbon sink over the growing season. However, high abundance of Carex lasiocarpa 10 years post-treatment led to higher CH 4 emissions than the reference ecosystem. Successful establishment of wetland vegetation is attributed to the area being surrounded by undisturbed fens that can provide a local source of plant propagules. Bryophyte expansion was less successful than vascular plants, likely due to episodic flooding and shading from the sedge communities. Therefore, careful management of water levels to just below the peat surface is needed if reference vegetation community recovery is the goal of restoration. Water level management will also play a key role in controlling CH 4 emissions to maximize carbon sequestration potential., (© 2023. The Author(s).)