scholarly journals Microbial Communities in a High Arctic Polar Desert Landscape

2016 ◽  
Vol 7 ◽  
Author(s):  
Clare M. McCann ◽  
Matthew J. Wade ◽  
Neil D. Gray ◽  
Jennifer A. Roberts ◽  
Casey R. J. Hubert ◽  
...  
Keyword(s):  
Microbial Communities ◽  
High Arctic ◽  
Polar Desert ◽  
Desert Landscape

scholarly journals Comparing Rock-inhabiting Microbial Communities in Different Rock Types from a High Arctic Polar Desert

2018 ◽  
Author(s):  
Yong-Hoe Choe ◽  
Mincheol Kim ◽  
Jusun Woo ◽  
Mi Jung Lee ◽  
Jong Ik Lee ◽  
...  
Keyword(s):  
Microbial Communities ◽  
High Arctic ◽  
Polar Desert ◽  
Rock Types

Vascular plant reproduction, establishment, and growth and the effects of cryptogamic crusts within a polar desert ecosystem, Devon Island, N.W.T., Canada

1999 ◽  
Vol 77 (5) ◽  
pp. 623-636 ◽  
Author(s):  
L C Bliss ◽  
W G Gold
Keyword(s):  
Plant Reproduction ◽  
High Arctic ◽  
Degree Days ◽  
Polar Desert ◽  
Devon Island ◽  
Warm Summer ◽  
Viable Seeds ◽  
Desert Landscape ◽  
Cryptogamic Crusts ◽  
Cryptogamic Crust

Most of the ice-free lands within the Canadian High Arctic are classified as polar desert (44%) or semidesert (49%). Much of this desert landscape supports no more than 6-10 vascular species that provide 1-3% cover and cryptogamic organisms that occupy 0-5% cover on the soil surface. The barrenness of these lands results from a short growing season and low summer temperatures that limit plant growth and the production of viable seeds. Limited areas have a 50-80% cover of cryptogamic crust and an 8-12% cover of vascular plants. These are areas in which surfaces remain moist for considerable periods in summer from snowflush waters. Where such cryptogamic soil crusts develop, they play a central role in soil development and nitrogen fixation. The two major components of this study were (i) an examination of fundamental reproductive, establishment, and growth characteristics of polar desert plants in the field and (ii) the relationship of these characteristics to environmental conditions in areas with and without cryptogamic crusts. Summer conditions during the study ranged from unusually warm (1991; 252 degree-days) to unusually cool (1992; 123 degree-days) with two average years (1994 and 1995; 172 and 166 degree-days, respectively). Differences in reproduction and establishment among these summers included (i) higher germination ability of seeds produced in the warm summer (1991) compared with more average summers (1994 and 1995) and (ii) significant seedling occurrence only in the average summers of 1994 and 1995. Seedling densities were much higher at crusted (206 seedlings/m2) than noncrusted sites (26 seedlings/m2). In both sites, root elongation of seedlings and older plants were significantly greater than shoot elongation, yet in established plants, shoot biomass was much greater than root biomass (root/shoot ratios from 0.1 to 0.3). Reproductive attributes varied among the species examined. Saxifraga caespitosa L. produced much smaller seeds then Draba corymbosa R. Br. ex DC. and Papaver radicatum Rottb., but the largest seeds of S. caespitosa (produced in the warm summer of 1991) had much higher germination rates than any seeds of the other species. Based on an analysis of population age structures, seedling survivorship was low for all species but was especially low for S. caespitosa, despite its higher germination rates. All species were slow to germinate, with isolated seeds under ideal controlled conditions requiring a minimum of 20-30 days at a 20°C day and 15°C night. Seed germination in excised soil blocks under comparable conditions averaged 36-48 days. We believe these polar desert plant species lack special attributes to uniquely exploit the environment of these very stressful locations. Rather, they are simply adept at surviving the rigors experienced there. The same species grow much larger, flower and fruit more abundantly, and produce more viable seeds in high arctic environments more favorable than polar deserts, such as lowland polar oases (e.g., Truelove Lowland, Devon Island, Canada). Within the harsh polar desert landscape of the High Arctic, the presence of a cryptogamic crust that retains surface moisture, prevents soil churning, and includes nitrogen-fixing organisms provides a more favorable habitat for plant reproduction, establishment, and growth.Key words: High Arctic, plant reproduction, plant establishment, plant growth, cryptogamic crust, polar desert, Devon Island.

scholarly journals Distinct Microbial Communities in Adjacent Rock and Soil Substrates on a High Arctic Polar Desert

2021 ◽  
Vol 11 ◽  
Author(s):  
Yong-Hoe Choe ◽  
Mincheol Kim ◽  
Yoo Kyung Lee
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Extreme Environments ◽  
Chemical Properties ◽  
Terrestrial Ecosystems ◽  
High Arctic ◽  
Polar Regions ◽  
Polar Desert ◽  
Arctic Soils ◽  
Diversity Assessment

Understanding microbial niche variability in polar regions can provide insights into the adaptive diversification of microbial lineages in extreme environments. Compositions of microbial communities in Arctic soils are well documented but a comprehensive multidomain diversity assessment of rocks remains insufficiently studied. In this study, we obtained two types of rocks (sandstone and limestone) and soils around the rocks in a high Arctic polar desert (Svalbard), and examined the compositions of archaeal, bacterial, fungal, and protistan communities in the rocks and soils. The microbial community structure differed significantly between rocks and soils across all microbial groups at higher taxonomic levels, indicating that Acidobacteria, Gemmatimonadetes, Latescibacteria, Rokubacteria, Leotiomycetes, Pezizomycetes, Mortierellomycetes, Sarcomonadea, and Spirotrichea were more abundant in soils, whereas Cyanobacteria, Deinococcus-Thermus, FBP, Lecanoromycetes, Eurotiomycetes, Trebouxiophyceae, and Ulvophyceae were more abundant in rocks. Interestingly, fungal communities differed markedly between two different rock types, which is likely to be ascribed to the predominance of distinct lichen-forming fungal taxa (Verrucariales in limestone, and Lecanorales in sandstone). This suggests that the physical or chemical properties of rocks could be a major determinant in the successful establishment of lichens in lithic environments. Furthermore, the biotic interactions among microorganisms based on co-occurrence network analysis revealed that Polyblastia and Verrucaria in limestone, and Atla, Porpidia, and Candelariella in sandstone play an important role as keystone taxa in the lithic communities. Our study shows that even in niches with the same climate regime and proximity to each other, heterogeneity of edaphic and lithic niches can affect microbial community assembly, which could be helpful in comprehensively understanding the effects of niche on microbial assembly in Arctic terrestrial ecosystems.

scholarly journals Microbial Community Structure in Lake and Wetland Sediments from a High Arctic Polar Desert Revealed by Targeted Transcriptomics

PLoS ONE ◽  
2014 ◽  
Vol 9 (3) ◽  
pp. e89531 ◽  
Author(s):  
Magdalena K. Stoeva ◽  
Stéphane Aris-Brosou ◽  
John Chételat ◽  
Holger Hintelmann ◽  
Philip Pelletier ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Microbial Community Structure ◽  
High Arctic ◽  
Polar Desert

scholarly journals An estimate of ice wedge volume for a High Arctic polar desert environment, Fosheim Peninsula, Ellesmere Island

2018 ◽  
Vol 12 (11) ◽  
pp. 3589-3604 ◽  
Author(s):  
Claire Bernard-Grand'Maison ◽  
Wayne Pollard
Keyword(s):  
Satellite Imagery ◽  
Regional Scale ◽  
High Arctic ◽  
Ellesmere Island ◽  
The Arctic ◽  
Ground Ice ◽  
Polar Desert ◽  
Ice Volume ◽  
Carbon Release ◽  
Wedge Volume

Abstract. Quantifying ground-ice volume on a regional scale is necessary to assess the vulnerability of permafrost landscapes to thaw-induced disturbance like terrain subsidence and to quantify potential carbon release. Ice wedges (IWs) are a ubiquitous ground-ice landform in the Arctic. Their high spatial variability makes generalizing their potential role in landscape change problematic. IWs form polygonal networks that are visible on satellite imagery from surface troughs. This study provides a first approximation of IW ice volume for the Fosheim Peninsula, Ellesmere Island, a continuous permafrost area characterized by polar desert conditions and extensive ground ice. We perform basic GIS analyses on high-resolution satellite imagery to delineate IW troughs and estimate the associated IW ice volume using a 3-D subsurface model. We demonstrate the potential of two semi-automated IW trough delineation methods, one newly developed and one marginally used in previous studies, to increase the time efficiency of this process compared to manual delineation. Our methods yield acceptable IW ice volume estimates, validating the value of GIS to estimate IW volume on much larger scales. We estimate that IWs are potentially present on 50 % of the Fosheim Peninsula (∼3000 km2), where 3.81 % of the top 5.9 m of permafrost could be IW ice.

High Arctic summer warming tracked by increased Cassiope tetragona growth in the world's northernmost polar desert

2017 ◽  
Vol 23 (11) ◽  
pp. 5006-5020 ◽  
Author(s):  
Stef Weijers ◽  
Agata Buchwal ◽  
Daan Blok ◽  
Jörg Löffler ◽  
Bo Elberling
Keyword(s):  
High Arctic ◽  
Polar Desert ◽  
Cassiope Tetragona ◽  
Summer Warming ◽  
Arctic Summer

scholarly journals In Situ Field Sequencing and Life Detection in Remote (79°26′N) Canadian High Arctic Permafrost Ice Wedge Microbial Communities

2017 ◽  
Vol 8 ◽  
Author(s):  
J. Goordial ◽  
Ianina Altshuler ◽  
Katherine Hindson ◽  
Kelly Chan-Yam ◽  
Evangelos Marcolefas ◽  
...  
Keyword(s):  
Microbial Communities ◽  
High Arctic ◽  
Canadian High Arctic ◽  
Ice Wedge ◽  
Life Detection

scholarly journals High Bacterial Diversity of Biological Soil Crusts in Water Tracks over Permafrost in the High Arctic Polar Desert

PLoS ONE ◽  
2013 ◽  
Vol 8 (8) ◽  
pp. e71489 ◽  
Author(s):  
Blaire Steven ◽  
Marie Lionard ◽  
Cheryl R. Kuske ◽  
Warwick F. Vincent
Keyword(s):  
Bacterial Diversity ◽  
High Arctic ◽  
Biological Soil Crusts ◽  
Polar Desert ◽  
Soil Crusts

scholarly journals Water tracks in the High Arctic: a hydrological network dominated by rapid subsurface flow through patterned ground

2017 ◽  
Vol 3 (2) ◽  
pp. 334-353 ◽  
Author(s):  
Michel Paquette ◽  
Daniel Fortier ◽  
Warwick F. Vincent
Keyword(s):  
Active Layer ◽  
Cold Water ◽  
High Arctic ◽  
Canadian High Arctic ◽  
Patterned Ground ◽  
Arctic Water ◽  
Near Surface ◽  
Polar Desert ◽  
Flow Through

Water tracks play a major role in the headwater basin hydrology of permafrost landscapes in Alaska and Antarctica, but less is known about these features in the High Arctic. We examined the physical and hydrological properties of water tracks on Ward Hunt Island, a polar desert site in the Canadian High Arctic, to evaluate their formation process and to compare with water tracks reported elsewhere. These High Arctic water tracks flowed through soils that possessed higher near-surface organic carbon concentrations, higher water content, and coarser material than the surrounding soils. The water track morphology suggested they were initiated by a combination of sorting, differential frost heaving, and eluviation. The resultant network of soil conduits, comparable to soil pipes, dominated the hydrology of the slope. The flow of cold water through these conduits slowed down the progression of the thawing front during summer, making the active layer consistently shallower relative to adjacent soils. Water tracks on Ward Hunt Island, and in polar desert catchments with these features elsewhere in the High Arctic, strongly influence slope hydrology and active-layer properties while also affecting vegetation distribution and the quality of runoff to the downstream lake.

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