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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, [delta][sup.13]C, [delta][sup.15]N, 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. Key words: organic soil, bulk density, mechanical mounding, C/N ratio, stable isotopes Les lignes sismiques sont des perturbations lineaires importantes dans la region boreale du Canada qui ont des consequences a grande echelle sur la faune et la fonction des ecosystemes. Meme si on a observe que la restauration des lignes sismiques ameliore la croissance et la survie des arbres, on a demontre que son application dans les tourbieres modifie les fonctions de l'ecosysteme telles que l'hydrologie et le stockage du carbone. La methode de restauration active la plus courante s'appelle le buttage mecanique oU la technique classique inverse le profil de la tourbe. De nouvelles methodes de buttage qui maintiennent le profil de la tourbe peuvent presenter des avantages en preservant la vegetation existante et en reduisant les perturbations. Pour determiner les effets de differentes methodes de buttage sur la qualite du sol, on a preleve et analyse des carottes de tourbe sur deux sites differents pour confirmer diverses proprietes du sol (rapport C/N, [delta][sup.13]C, [delta][sup.15]N, indices d'humification par spectroscopie infrarouge a transformee de Fourier (FTIR)). Des etudes de la vegetation ont egalement ete menees. Les deux sites correspondent a un ensemble de lignes sismiques traversant des tourbieres pauvres en Alberta. La methode classique a ete utilisee pour traiter un site tandis que l'autre a ete traite avec deux nouvelles methodes de buttage. Le buttage mecanique classique a augmente de maniere significative le degre de decomposition, ce qui indique une qualite inferieure du substrat. Le buttage mecanique a egalement reduit considerablement la couverture de mousse et a introduit de grandes quantites de couverture de sol nu. Les deux methodes de buttage plus recentes n'ont pas entraine ces changements et etaient largement comparables aux proprietes de la tourbe naturelle et aux communautes vegetales. La preservation du profil de la tourbe dans les nouvelles methodes de buttage peut favoriser un retour plus rapide des fonctions de l'ecosysteme. [Traduit par la Redaction] Mots-cles : sol organique, densite apparente, buttage mecanique, rapport C/N, isotopes stables, Introduction An estimated 345 000 km of seismic lines covering 1910 [km.sup.2] have been created in all types of peatlands in the province of Alberta, Canada, for oil and gas [...]

Land-use changes and anthropogenic disturbances are major threats to biodiversity, affecting ecosystem function and recovery. In boreal Alberta, Canada, petroleum development has led to extensive landscape fragmentation, notably through linear clearings created for seismic exploration that remove surface vegetation and microtopography. Despite partial recovery on forested seismic lines, peatland recovery is often arrested, impacting wildlife and carbon dynamics. Restoration efforts employ silviculture techniques to create microtopography and foster tree growth, but the efficacy of restoration treatments in restoring peatland plant diversity remains uncertain. We compared taxonomic, phylogenetic, and functional diversity of understory plant communities across treated and untreated seismic lines, alongside reference sites in treed bogs and fens. Treated lines generally had a twofold increase in plant height, leaf dry matter content, and foliar nitrogen and phosphorus contents compared to reference sites. In bogs, treated lines differed from reference conditions driven by increases in herbaceous taxa, while fens displayed disparities mainly in taxonomic and phylogenetic diversity. Differential responses of bogs and fens underline the necessity for tailored management strategies. Changes in plant diversity away from restoration targets have implications for ecosystem recovery, emphasizing the importance of long-term monitoring to evaluate the effectiveness of silviculture techniques in restoring boreal peatland plant communities. [ABSTRACT FROM AUTHOR]

Studies in recent decades have shown strong evidence of physical and biological changes in the Arctic tundra, largely in response to rapid rates of warming. Given the important implications of these changes for ecosystem services, hydrology, surface energy balance, carbon budgets, and climate feedbacks, research on the trends and patterns of these changes is becoming increasingly important and can help better constrain estimates of local, regional, and global impacts as well as inform mitigation and adaptation strategies. Despite this great need, scientific understanding of tundra ecology and change remains limited, largely due to the inaccessibility of this region and less intensive studies compared to other terrestrial biomes. A synthesis of existing datasets from past field studies can make field data more accessible and open up possibilities for collaborative research as well as for investigating and informing future studies. Here, we synthesize field datasets of vegetation and active-layer properties from the Alaskan tundra, one of the most well-studied tundra regions. Given the potentially increasing intensive fire regimes in the tundra, fire history and severity attributes have been added to data points where available. The resulting database is a resource that future investigators can employ to analyze spatial and temporal patterns in soil, vegetation, and fire disturbance-related environmental variables across the Alaskan tundra. This database, titled the Synthesized Alaskan Tundra Field Database (SATFiD), can be accessed at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) for Biogeochemical Dynamics (Chen et al., 2023: 10.3334/ORNLDAAC/2177). [ABSTRACT FROM AUTHOR]

Arctic tundra largely in response to exceptionally rapid rates of warming. Given the important implications of these changes on ecosystem services, hydrology, surface energy balance, carbon budgets, and climate feedbacks, research on the trends and patterns of these changes is becoming increasingly important and can help better constrain estimates of local, regional, and global impacts as well as inform mitigation and adaptation strategies. Despite this high need, scientific understanding of tundra ecology and change remains limited largely due to the inaccessibility of this region and less intensive study compared to other terrestrial biomes. A synthesis of existing datasets from past field studies can make field data more accessible and open up possibilities for collaborative research as well as for investigating and informing future studies. Here, we synthesize field datasets of vegetation, and active layer properties from the Alaskan tundra, one of the most well-studied tundra regions. Given the potential increasingly intensive fire regimes in the tundra, fire history and severity attributes have been added to data points where available. The resulting database is a resource that future investigators can employ to analyze spatial and temporal patterns in soil, vegetation, and fire disturbance-related environmental variables across the Alaskan tundra. This database, titled Synthesized Alaskan Tundra Field Database (SATFiD), can be accessed at the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) for Biogeochemical Dynamics (Chen et al., 2023: https://doi.org/10.3334/ORNLDAAC/2177). [ABSTRACT FROM AUTHOR]

Northern peatlands have cooled the global climate by accumulating large quantities of soil carbon (C) over thousands of years. Maintaining the C sink function of these peatlands and their immense long‐term soil C stores is critical for achieving net‐zero global carbon dioxide (CO2) emissions by 2050 to mitigate climate warming. One‐quarter of the world's northern peatlands are in Canada, with these mostly intact ecosystems providing a global C service that is increasingly recognized as a critical part of nature‐based solutions to combat climate change. However, land‐use change and other disturbances threaten these globally important stores of "irrecoverable C" (that is, soil C lost to disturbance that will take centuries to recover). Inadequate policy safeguards to avoid conversion and degradation, and the limited quantification and reporting of peatland greenhouse‐gas emissions and removals, increase the vulnerability of these peatlands. Targeted policies from local to global scales will be needed for improved decision making and incentivizing long‐term C management of northern peatlands. [ABSTRACT FROM AUTHOR]

Oil and gas exploration has resulted in over 300,000 km of linear disturbances, known as seismic lines, throughout boreal peatlands across Canada. Sites are left with altered hydrologic and topographic conditions that prevent tree re-establishment. Restoration efforts have concentrated on tree recovery through mechanical mounding to re-create microtopography and support planted tree seedlings to block sightlines and deter the use of lines by wolves, but little is known about the impact of seismic line disturbance or restoration on peatland carbon cycling. This study looked at two mounding treatments and compared summer growing season carbon dioxide and methane fluxes to untreated lines and natural reference areas of a wooded fen in the first two years post-restoration. We found no significant differences in net ecosystem CO2 exchange, but untreated seismic lines were slightly more productive than natural reference areas and mounding treatments. Both restoration treatments increased ecosystem respiration, decreased net productivity by 6–21 g CO2 m−2 d−1, and created areas of increased methane emissions, including an increase in the contribution of ebullition, of up to 2000 mg CH4 m−2 d−1 over natural and untreated lines. Further research on this site to assess the longer-term impacts of restoration, as well as application on other sites with varied conditions, will help determine if these restoration practices are effective at restoring carbon cycling. [ABSTRACT FROM AUTHOR]

Across Canada's boreal forest, disturbances from in situ oil sands mining, including well‐pads, significantly impact vast areas of the landscape. The creation of well‐pads requires removal of vegetation and placement of mineral fill, which essentially stops any carbon (C) sequestration on the once peatland ecosystem. It is important that, once no longer in use, these well‐pads are restored as long‐term C (peat) accumulation is what defines peatland ecosystem. However, little is known about the recovery of greenhouse gas exchange post‐restoration of these features. We studied a decommissioned well‐pad located in a treed poor fen that was restored using three soil adjustment treatments (SATs): (1) complete mineral fill removal (Peat‐Dec); (2) partial pad removal and burial under peat layer (BUPL); and (3) mixing mineral and peat by inversion (Mixed‐P‐M). The recreated peat surface was revegetated with donor peatland species using the moss layer transfer technique (MLTT). The objectives of this paper were to (1) quantify plot‐scale seasonal carbon dioxide (CO2) and methane (CH4) exchange of the SATs, 2–4 years post‐restoration compared to reference sites and (2) determine the influence of several environmental variables on CO2 and CH4 exchange. All SATs proved effective in recreating a soil surface needed to support peatland vegetation as shown by similar rates of net ecosystem exchange (NEE). Equally, both types of vegetation reintroduced led this site on a trajectory toward functioning as a net C sink. [ABSTRACT FROM AUTHOR]

Explores legal conflicts that arise between seniority principles and affirmative action goals when public schools must reduce their workforces. Suggests that minority students' right to equal education, which demands a substantial minority faculty presence, should be a prevailing concern in dealing with layoffs. (Author/MJL)

Boreal peatlands represent a globally important store of carbon, and disturbances such as wildfire can have a negative feedback to the climate. Understanding how carbon exchange and greenhouse gas (GHG) dynamics are impacted after a wildfire is important, especially as boreal peatlands may be vulnerable to changes in wildfire regime under a rapidly changing climate. Yet, given this vulnerability, there is very little in the literature on the impact such fires have on methane (CH4) emissions. This study investigated the effect of wildfire on CH4 emissions at a boreal fen near Fort McMurray, AB, Canada, that was partially burned by the Horse River Wildfire in 2016. We measured CH4 emissions and environmental variables (2017-2018) and CH4 production potential (2018) in two different microform types (hummocks and hollows) across a burn severity gradient (unburned (UB), moderately burned (MB) and severely burned (SB)). Results indicated a switch in the typical understanding of boreal peatland CH4 emissions. For example, emissions were much lower in the MB and SB hollows in both years compared to UB hollows. Interestingly, across the burned sites, hummocks had higher fluxes in 2017 than hollows at the MB and SB sites. We found typically higher emissions at the UB site where the water table was close to the surface. However, at the burned sites, no relationship was found between CH4 emissions and water table, even under similar hydrological conditions. This further strengthens the argument on the overriding influence of fire. There was also significantly higher CH4 production potential from the UB site than the burned sites. The reduction in CH4 emissions and production in the hollows at burned sites highlights the sensitivity of hollows to fire, removing labile organic material for potential methanogenesis. The previously demonstrated resistance of hummocks to fire also results in limited impact to CH4 emissions and likely faster recovery to pre-fire rates. Given the potential initial net cooling effect resulting from a reduction in CH4 emissions, it is important that the radiative effect of all GHG following wildfire across peatlands is taken into account. [ABSTRACT FROM AUTHOR]