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Kaplan Pastíriková L, Hrbáček F, Uxa T, Láska K. Permafrost table temperature and active layer thickness variability on James Ross Island, Antarctic Peninsula, in 2004-2021. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 869:161690. [PMID: 36657667 DOI: 10.1016/j.scitotenv.2023.161690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 12/22/2022] [Accepted: 01/14/2023] [Indexed: 06/17/2023]
Abstract
Climate change and its impacts on sensitive polar ecosystems are relatively little studied in Antarctic regions. Permafrost and active layer changes over time in periglacial regions of the world are important indicators of climate variability. These changes (e. g. permafrost degradation, increasing of the active layer thickness) can have a significant impact on Antarctic terrestrial ecosystems. The study site (AWS-JGM) is located on the Ulu Peninsula in the north of James Ross Island. Ground temperatures at depths of 5, 50, and 75 cm have been measured at the site since 2011, while air temperature began to be measured in 2004. The main objective is to evaluate the year-to-year variability of the reconstructed temperature of the top of the permafrost table and the active layer thickness (ALT) since 2004 based on air temperature data using TTOP and Stefan models, respectively. The models were verified against direct observations from a reference period 2011/12-2020/21 showing a strong correlation of 0.95 (RMSE = 0.52) and 0.84 (RMSE = 3.54) for TTOP and Stefan models, respectively. The reconstructed average temperature of the permafrost table for the period 2004/05-2020/21 was -5.8 °C with a trend of -0.1 °C/decade, while the average air temperature reached -6.6 °C with a trend of 0.6 °C/decade. Air temperatures did not have an increasing trend throughout the period, but in the first part of the period (2004/05-2010/11) showed a decreasing tendency (-1.3 °C/decade). In the period 2011/12-2020/21, it was a warming of 1.9 °C/decade. The average modelled ALT for the period 2004/05-2020/21 reached a value of 60cm with a trend of -1.6 cm/decade. Both models were found to provide reliable results, and thus they significantly expand the information about the permafrost and ALT, which is necessary for a better understanding of their spatiotemporal variability and the impact of climate change on the cryosphere.
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Affiliation(s)
| | - Filip Hrbáček
- Department of Geography, Masaryk University, Brno, Czech Republic
| | - Tomáš Uxa
- Institute of Geophysics, Czech Academy of Sciences, Prague, Czech Republic
| | - Kamil Láska
- Department of Geography, Masaryk University, Brno, Czech Republic
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Diversity, ecology, and community structure of the terrestrial diatom flora from Ulu Peninsula (James Ross Island, NE Antarctic Peninsula). Polar Biol 2022. [DOI: 10.1007/s00300-022-03038-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Snopková K, Dufková K, Chamrád I, Lenobel R, Čejková D, Kosina M, Hrala M, Holá V, Sedláček I, Šmajs D. Pyocin-mediated antagonistic interactions in Pseudomonas spp. isolated in James Ross Island, Antarctica. Environ Microbiol 2021; 24:1294-1307. [PMID: 34735036 DOI: 10.1111/1462-2920.15809] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/15/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022]
Abstract
Interactions within bacterial communities are frequently mediated by the production of antimicrobial agents. Despite the increasing interest in research of new antimicrobials, studies describing antagonistic interactions among cold-adapted microorganisms are still rare. Our study assessed the antimicrobial interactions of 36 Antarctic Pseudomonas spp. and described the genetic background of these interactions in selected strains. The overall bacteriocinogeny was greater compared to mesophilic Pseudomonas non-aeruginosa species. R-type tailocins were detected on transmission electron micrographs in 16 strains (44.4%); phylogenetic analysis of the corresponding gene clusters revealed that the P. prosekii CCM 8878 tailocin was related to the Rp3 group, whereas the tailocin in Pseudomonas sp. CCM 8880 to the Rp4 group. Soluble antimicrobials were produced by eight strains (22.-2%); gene mining found pyocin L homologues in the genomes of P. prosekii CCM 8881 and CCM 8879 and pyocin S9-like homologues in P. prosekii CCM 8881 and Pseudomonas sp. CCM 8880. Analysis of secretomes confirmed the production of all S- and L-type pyocin genes. Our results suggest that bacteriocin-based inhibition plays an important role in interactions among Antarctic soil bacteria, and these native, cold-adapted microorganisms could be a promising source of new antimicrobials.
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Affiliation(s)
- Kateřina Snopková
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Kristýna Dufková
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Ivo Chamrád
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 241/27, Olomouc-Holice, 779 00, Czech Republic
| | - René Lenobel
- Laboratory of Growth Regulators, Faculty of Science, Palacký University and Institute of Experimental Botany of the Czech Academy of Sciences, Šlechtitelů 241/27, Olomouc-Holice, 779 00, Czech Republic
| | - Darina Čejková
- Veterinary Research Institute, Hudcova 296/70, Brno, 621 00, Czech Republic
| | - Marcel Kosina
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Matěj Hrala
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - Veronika Holá
- Faculty of Medicine, Institute for Microbiology, Masaryk University and St. Anne's University Hospital Brno, Pekařská 664/53, Brno, 656 91, Czech Republic
| | - Ivo Sedláček
- Department of Experimental Biology, Czech Collection of Microorganisms, Faculty of Science, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
| | - David Šmajs
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 753/5, Brno, 625 00, Czech Republic
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Mitigation of Arctic Tundra Surface Warming by Plant Evapotranspiration: Complete Energy Balance Component Estimation Using LANDSAT Satellite Data. REMOTE SENSING 2020. [DOI: 10.3390/rs12203395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Global climate change is expected to cause a strong temperature increase in the polar regions, accompanied by a reduction in snow cover. Due to a lower albedo, bare ground absorbs more solar energy and its temperature can increase more. Here, we show that vegetation growth in such bare ground areas can efficiently mitigate surface warming in the Arctic, thanks to plant evapotranspiration. In order to establish a comprehensive energy balance for the Arctic land surface, we used an ensemble of methods of ground-based measurements and multispectral satellite image analysis. Our estimate is that the low vegetation of polar tundra transforms 26% more solar energy into evapotranspiration than bare ground in clear sky weather. Due to its isolation properties, vegetation further reduces ground heat flux under the surface by ~4%, compared to bare areas, thus lowering the increase in subsurface temperature. As a result, ~22% less solar energy can be transformed into sensible heat flux at vegetated surfaces as opposed to bare ground, bringing about a decrease in surface temperature of ~7.8 °C.
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The Summer Surface Energy Budget of the Ice-Free Area of Northern James Ross Island and Its Impact on the Ground Thermal Regime. ATMOSPHERE 2020. [DOI: 10.3390/atmos11080877] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Despite the key role of the surface energy budget in the global climate system, such investigations are rare in Antarctica. In this study, the surface energy budget measurements from the largest ice-free area on northern James Ross Island, in Antarctica, were obtained. The components of net radiation were measured by a net radiometer, while sensible heat flux was measured by a sonic anemometer and ground heat flux by heat flux plates. The surface energy budget was compared with the rest of the Antarctic Peninsula Region and selected places in the Arctic and the impact of surface energy budget components on the ground thermal regime was examined. Mean net radiation on James Ross Island during January–March 2018 reached 102.5 W m−2. The main surface energy budget component was the latent heat flux, while the sensible heat flux values were only 0.4 W m−2 lower. Mean ground heat flux was only 0.4 Wm-2, however, it was negative in 47% of January–March 2018, while it was positive in the rest of the time. The ground thermal regime was affected by surface energy budget components to a depth of 50 cm. The strongest relationship was found between ground heat flux and ground surface temperature. Further analysis confirmed that active layer refroze after a sequence of three days with negative ground heat flux even in summer months. Daily mean net radiation and ground heat flux were significantly reduced when cloud amount increased, while the influence of snow cover on ground surface temperature was negligible.
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Hrbáček F, Oliva M, Fernández JR, Kňažková M, de Pablo MA. Modelling ground thermal regime in bordering (dis)continuous permafrost environments. ENVIRONMENTAL RESEARCH 2020; 181:108901. [PMID: 31784076 DOI: 10.1016/j.envres.2019.108901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 06/10/2023]
Abstract
Permafrost controls geomorphological dynamics in maritime Antarctic ecosystems. Here, we analyze and model ground thermal regime in bordering conditions between continuous and discontinuous permafrost to better understand its relationship with the timing of glacial retreat. In February 2017, a transect including 10 sites for monitoring ground temperatures was installed in the eastern fringe of Byers Peninsula (Livingston Island, northern Antarctic Peninsula), together with one station recording air temperatures and snow thickness. The sites were selected following the Mid-Late Holocene deglaciation of the area at a distance ranging from 0.30 to 3.15 km from the current Rotch Dome glacier front. The transect provided data on the effects of topography, snow cover and the timing of ice-free exposure, on the ground thermal regime. From February 2017 to February 2019, the mean annual air temperature was -2.0 °C, which was >0.5 °C higher than 1986-2015 average in the Western Antarctic Peninsula region. Mean annual ground temperature at 10 cm depth varied between 0.3 and -1.1 °C, similar to the modelled Temperatures on the Top of the Permafrost (TTOP) that ranged from 0.06 ± 0.08 °C to -1.33 ± 0.07 °C. The positive average temperatures at the warmest site were related to the long-lasting presence of snow which favoured warmer ground temperatures and may trigger permafrost degradation. The role of other factors (topography, and timing of the deglaciation) explained intersite differences, but the overall effect was not as strong as snow cover.
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Affiliation(s)
- Filip Hrbáček
- Department of Geography, Faculty of Science, Masaryk University, Brno, Czech Republic.
| | - Marc Oliva
- Department of Geography, Universitat de Barcelona, C/ Montalegre 6-8, 3r, 08001, Barcelona, Spain
| | | | - Michaela Kňažková
- Department of Geography, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Miguel Angel de Pablo
- Department of Geology, Geography and Environment, University of Alcalá, 28805, Madrid, Spain
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Sedláček I, Pantůček R, Holochová P, Králová S, Staňková E, Vrbovská V, Šedo O, Švec P, Busse HJ. Hymenobacter humicola sp. nov., isolated from soils in Antarctica. Int J Syst Evol Microbiol 2019; 69:2755-2761. [PMID: 31237531 DOI: 10.1099/ijsem.0.003555] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A set of three psychrotrophic bacterial strains was isolated from different soil samples collected at the deglaciated northern part of James Ross Island (Antarctica) in 2014. All isolates were rod-shaped, Gram-stain-negative, non-motile, catalase-positive and oxidase-negative, and produced moderately slimy red-pink pigmented colonies on Reasoner's 2A (R2A) agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, whole-genome sequencing, automated ribotyping, MALDI-TOF MS, chemotaxonomy methods and extensive biotyping using conventional tests and commercial identification kits was applied to the isolates in order to clarify their taxonomic position. Phylogenetic analysis based on the 16S rRNA gene showed that all isolates belonged to the genus Hymenobacter with the closest relative being Hymenobacter aerophilus DSM 13606T, exhibiting 98.5 % 16S rRNA gene pairwise similarity to the reference isolate P6312T. Average nucleotide identity values calculated from the whole-genome sequencing data proved that P6312T represents a distinct Hymenobacter species. The major components of the cellular fatty acid composition were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C16 : 1 ω5c, summed feature 4 (C17 : 1 anteiso B/iso I), C15 : 0 anteiso and C15 : 0 iso. The menaquinone system of strain P6312T contained MK-7 as the major respiratory quinone. The predominant polar lipids were phosphatidylethanolamine and an unidentified phospholipid. Moderate to minor amounts of three unidentified polar lipids, four unidentified aminophospholipids, one unidentified glycolipid and one unidentified phospholipid were also present. Based on the obtained results, we propose a novel species for which the name Hymenobacterhumicola sp. nov. is suggested, with the type strain P6312T (=CCM 8763T=LMG 30612T).
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Affiliation(s)
- Ivo Sedláček
- Czech Collection of Microorganisms, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Roman Pantůček
- Section of Genetics and Molecular Biology, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Pavla Holochová
- Czech Collection of Microorganisms, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Stanislava Králová
- Czech Collection of Microorganisms, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Eva Staňková
- Czech Collection of Microorganisms, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Veronika Vrbovská
- Section of Genetics and Molecular Biology, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Ondrej Šedo
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Pavel Švec
- Czech Collection of Microorganisms, Department of Experimental Biology, Masaryk University, Brno, Czech Republic
| | - Hans-Jürgen Busse
- Institut für Mikrobiologie, Veterinärmedizinische Universität Wien, Veterinärplatz 1, A-1210 Wien, Austria
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Králová S, Busse HJ, Švec P, Mašlaňová I, Staňková E, Barták M, Sedláček I. Flavobacterium circumlabens sp. nov. and Flavobacterium cupreum sp. nov., two psychrotrophic species isolated from Antarctic environmental samples. Syst Appl Microbiol 2019; 42:291-301. [DOI: 10.1016/j.syapm.2018.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 12/02/2018] [Accepted: 12/14/2018] [Indexed: 10/27/2022]
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Bohuslavová O, Macek P, Redčenko O, Láska K, Nedbalová L, Elster J. Dispersal of lichens along a successional gradient after deglaciation of volcanic mesas on northern James Ross Island, Antarctic Peninsula. Polar Biol 2018. [DOI: 10.1007/s00300-018-2357-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Oliva M, Pereira P, Antoniades D. The environmental consequences of permafrost degradation in a changing climate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 616-617:435-437. [PMID: 29127797 DOI: 10.1016/j.scitotenv.2017.10.285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 06/07/2023]
Affiliation(s)
- M Oliva
- Department of Geography, University of Barcelona, Spain.
| | - P Pereira
- Environmental Management Center, Mykolas Romeris University, Vilnius, Lithuania
| | - D Antoniades
- Department of Géographie, Centre d'Études Nordiques, Université Laval, Canada
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