Microbiome structure and functional potential in permafrost soils of the Western Canadian Arctic

2021 ◽  
Author(s):  
Milan Varsadiya ◽  
Tim Urich ◽  
Gustaf Hugelius ◽  
Jiří Bárta
Keyword(s):  
Nifh Gene ◽  
Canadian Arctic ◽  
Microbial Transformation ◽  
Western Canada ◽  
Soil Horizons ◽  
Mcra Gene ◽  
Functional Potential ◽  
Permafrost Soils ◽  
Microbial Groups ◽  
Slow Growing

Abstract Substantial amounts of topsoil organic matter (OM) in Arctic Cryosols have been translocated by the process of cryoturbation into deeper soil horizons (cryoOM), reducing its decomposition. Recent Arctic warming deepens the Cryosols´ active layer, making more topsoil and cryoOM carbon accessible for microbial transformation. To quantify bacteria, archaea, and selected microbial groups (methanogens- mcrA gene and diazotrophs- nifH gene) and to investigate bacterial and archaeal diversity, we collected 83 soil samples from four different soil horizons of three distinct tundra types located in Qikiqtaruk (Hershel Island, Western Canada). In general, the abundance of bacteria and diazotrophs decreased from topsoil to permafrost, but not for cryoOM. No such difference was observed for archaea and methanogens. CryoOM was enriched with oligotrophic (slow-growing microorganism) taxa capable of recalcitrant OM degradation. We found distinct microbial patterns in each tundra type: topsoil from wet-polygonal tundra had the lowest abundance of bacteria and diazotrophs, but the highest abundance of methanogens. Wet-polygonal tundra, therefore, represented a hotspot for methanogenesis. Oligotrophic and copiotrophic (fast-growing microorganism) genera of methanogens and diazotrophs were distinctly distributed in topsoil and cryoOM, resulting in different rates of nitrogen flux into these horizons affecting OM vulnerability and potential CO2 and CH4 release.

scholarly journals Ground ice, organic carbon and soluble cations in tundra permafrost soils and sediments near a Laurentide ice divide in the Slave Geological Province, Northwest Territories, Canada

2020 ◽  
Vol 14 (12) ◽  
pp. 4341-4364
Author(s):  
Rupesh Subedi ◽  
Steven V. Kokelj ◽  
Stephan Gruber
Keyword(s):  
Organic Carbon ◽  
Landscape Change ◽  
Ice Sheet ◽  
Canadian Arctic ◽  
Landscape Changes ◽  
Ground Ice ◽  
Basal Ice ◽  
Permafrost Soils ◽  
Western Arctic ◽  
Mineral Soils

Abstract. The central Slave Geological Province is situated 450–650 km from the presumed spreading centre of the Keewatin Dome of the Laurentide Ice Sheet, and it differs from the western Canadian Arctic, where recent thaw-induced landscape changes in Laurentide ice-marginal environments are already abundant. Although much of the terrain in the central Slave Geological Province is mapped as predominantly bedrock and ice-poor, glacial deposits of varying thickness occupy significant portions of the landscape in some areas, creating a mosaic of permafrost conditions. Limited evidence of ice-rich ground, a key determinant of thaw-induced landscape change, exists. Carbon and soluble cation contents in permafrost are largely unknown in the area. Twenty-four boreholes with depths up to 10 m were drilled in tundra north of Lac de Gras to address these regional gaps in knowledge and to better inform projections and generalizations at a coarser scale. Excess-ice contents of 20 %–60 %, likely remnant Laurentide basal ice, are found in upland till, suggesting that thaw subsidence of metres to more than 10 m is possible if permafrost were to thaw completely. Beneath organic terrain and in fluvially reworked sediment, aggradational ice is found. The variability in abundance of ground ice poses long-term challenges for engineering, and it makes the area susceptible to thaw-induced landscape change and mobilization of sediment, solutes and carbon several metres deep. The nature and spatial patterns of landscape changes, however, are expected to differ from ice-marginal landscapes of western Arctic Canada, for example, based on greater spatial and stratigraphic heterogeneity. Mean organic-carbon densities in the top 3 m of soil profiles near Lac de Gras are about half of those reported in circumpolar statistics; deeper deposits have densities ranging from 1.3–10.1 kg C m−3, representing a significant additional carbon pool. The concentration of total soluble cations in mineral soils is lower than at previously studied locations in the western Canadian Arctic. This study can inform permafrost investigations in other parts of the Slave Geological Province, and its data can support scenario simulations of future trajectories of permafrost thaw. Preserved Laurentide basal ice can support new ways of studying processes and phenomena at the base of an ice sheet.

The Use of Gas Turbines in Gas Pipeline Service in Western Canada: Present and Future

1971 ◽  
Author(s):  
R. E. Stauffer
Keyword(s):  
Gas Turbines ◽  
High Efficiency ◽  
Canadian Arctic ◽  
Gas Pipeline ◽  
Western Canada ◽  
Fuel Gas ◽  
Aircraft Type

Existing gas pipeline facilities in Western Canada are outlined. The paper points out the trend away from industrial type gas turbines, and points out the advantages to using aircraft type gas turbines. The expansion of pipeline facilities to the Canadian Arctic and Alaska could prove to be a market for the new high efficiency aircraft type gas turbines. The fuel gas savings can be a significant factor when constructing the new line.

Amorphous silica pools in permafrost soils of the Central Canadian Arctic and the potential impact of climate change

2015 ◽  
Vol 124 (1-3) ◽  
pp. 441-459 ◽  
Author(s):  
Hanna Alfredsson ◽  
G. Hugelius ◽  
W. Clymans ◽  
J. Stadmark ◽  
P. Kuhry ◽  
...  
Keyword(s):  
Climate Change ◽  
Amorphous Silica ◽  
Canadian Arctic ◽  
Impact Of Climate Change ◽  
Permafrost Soils ◽  
Potential Impact

Fossil mosses, Beaufort Formation (Tertiary), Northwestern Banks Island, Western Canada Arctic

1971 ◽  
Vol 49 (7) ◽  
pp. 1089-1094 ◽  
Author(s):  
M. Kuc ◽  
L. V. Hills
Keyword(s):  
Canadian Arctic ◽  
Western Canada ◽  
Banks Island ◽  
Lake Sedimentation ◽  
Organic Remains

Thirteen fossil mosses belonging to eight genera were extracted from a woody sapropel found in the upper Beaufort Formation, northwestern Banks Island, Western Canadian Arctic. All belong to extant species.On the basis of the enclosing strata, moss fossils, and associated organic remains it is concluded that the sediments were deposited in a small, shallow body of water, in which lake sedimentation was both preceded and terminated by alluvial sedimentation.

Methanogenic Hydrocarbon Degradation: Evidence from Field and Laboratory Studies

2016 ◽  
Vol 26 (1-3) ◽  
pp. 227-242 ◽  
Author(s):  
Núria Jiménez ◽  
Hans H. Richnow ◽  
Carsten Vogt ◽  
Tina Treude ◽  
Martin Krüger
Keyword(s):  
Electron Acceptor ◽  
Oil Sands ◽  
Microbial Transformation ◽  
Hydrocarbon Degradation ◽  
Atmospheric Composition ◽  
The Novel ◽  
Deep Biosphere ◽  
Molecular Approaches ◽  
Coal Deposits ◽  
Microbial Groups

Microbial transformation of hydrocarbons to methane is an environmentally relevant process taking place in a wide variety of electron acceptor-depleted habitats, from oil reservoirs and coal deposits to contaminated groundwater and deep sediments. Methanogenic hydrocarbon degradation is considered to be a major process in reservoir degradation and one of the main processes responsible for the formation of heavy oil deposits and oil sands. In the absence of external electron acceptors such as oxygen, nitrate, sulfate or Fe(III), fermentation and methanogenesis become the dominant microbial metabolisms. The major end product under these conditions is methane, and the only electron acceptor necessary to sustain the intermediate steps in this process is CO<sub>2</sub>, which is itself a net product of the overall reaction. We are summarizing the state of the art and recent advances in methanogenic hydrocarbon degradation research. Both the key microbial groups involved as well as metabolic pathways are described, and we discuss the novel insights into methanogenic hydrocarbon-degrading populations studied in laboratory as well as environmental systems enabled by novel cultivation-based and molecular approaches. Their possible implications on energy resources, bioremediation of contaminated sites, deep-biosphere research, and consequences for atmospheric composition and ultimately climate change are also addressed.

In situ creep properties in ice-rich permafrost soil

1986 ◽  
Vol 23 (4) ◽  
pp. 504-514 ◽  
Author(s):  
K. W. Savigny ◽  
N. R. Morgenstern
Keyword(s):  
Canadian Arctic ◽  
Permafrost Soil ◽  
Creep Properties ◽  
Factors Affecting ◽  
Naturally Occurring ◽  
Permafrost Soils ◽  
Bear River ◽  
Creep Deformations ◽  
Significant Factors

An in situ analysis of naturally occurring creep has been carried out at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories. This is the third of four papers that describe the study. The borehole inclinometer system and monitoring procedures used to determine in situ movement are described. Significant factors affecting the accuracy of the system are assessed. External factors causing movement of the inclinometer casing are also assessed and movements caused by these factors are separated from natural ground movements. The magnitude and nature of naturally occurring creep deformations are discussed. Key words: Mackenzie Valley, pipelines, slopes, permafrost, soils, geotechnical, inclinometers, creep.

Geotechnical condition of slopes at a proposed pipeline crossing, Great Bear River valley, Northwest Territories

1986 ◽  
Vol 23 (4) ◽  
pp. 490-503 ◽  
Author(s):  
K. W. Savigny ◽  
N. R. Morgenstern
Keyword(s):  
Northwest Territories ◽  
Canadian Arctic ◽  
Field Investigation ◽  
Naturally Occurring ◽  
Clay Deposits ◽  
Permafrost Soils ◽  
Bear River ◽  
Valley Area ◽  
Pipeline Crossing

An in situ analysis of naturally occurring creep has been carried out in ice-rich permafrost soils underlying a slope at the proposed Canadian Arctic Gas pipeline crossing of Great Bear River in the Northwest Territories. This is the second of four papers that describe the study. Field investigation and instrument installation techniques are described and geological, geotechnical, and geothermal results are presented. The data presented here are intended to facilitate clear interpretation of deformation observations in the third paper. The data are representative of ice-rich glaciolacustrine clay deposits that are widespread in the mid-Mackenzie Valley area. Key words: Mackenzie Valley, pipelines, slopes, permafrost, soils, drilling, sampling, geotechnical, geothermal.

Comparisons of magnetic anomalies of lithospheric origin measured by satellite and airborne magnetometers over western Canada

1980 ◽  
Vol 17 (7) ◽  
pp. 876-887 ◽  
Author(s):  
R. A. Langel ◽  
R. L. Coles ◽  
M. A. Mayhew
Keyword(s):  
High Field ◽  
Canadian Arctic ◽  
Magnetic Anomalies ◽  
High Heat ◽  
Western Canada ◽  
Aeromagnetic Data ◽  
High Heat Flow ◽  
Crustal Magnetic Anomaly ◽  
Sverdrup Basin ◽  
Northern Portion

Crustal magnetic anomaly data from the Orbiting Geophysical Observatories 2, 4, and 6 (Pogo) satellites are compared with upward-continued aeromagnetic data between 50–85°N latitude and 220–260°E longitude. Agreement is good, both in anomaly location and in amplitude, giving confidence that it is possible to proceed with the derivation and interpretation of satellite anomaly maps in all parts of the globe. The data contain a magnetic high over the Alpha ridge suggesting continental composition and a magnetic low over the southern Canada basin and northern Canadian Arctic Islands (Sverdrup basin). The low in the Sverdrup basin corresponds to a region of high heat flow, suggesting a shallow Curie isotherm. A ridge of high field, with two distinct peaks in amplitude, is found over the northern portion of the platform deposits and a relative high is located in the central portion of the Churchill Province. No features are present to indicate a magnetic boundary between Slave and Bear Provinces, but a trend change is evident between Slave and Churchill Provinces. South of 60° latitude a broad magnetic low is located over very thick (40–50 km) crust, interpreted to be a region of low magnetization.

Sign in / Sign up

Export Citation Format

Share Document