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Engstrom CB, Quarmby LM. Satellite mapping of red snow on North American glaciers. SCIENCE ADVANCES 2023; 9:eadi3268. [PMID: 38000025 PMCID: PMC10672188 DOI: 10.1126/sciadv.adi3268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 10/25/2023] [Indexed: 11/26/2023]
Abstract
Red snow caused by blooms of microalgae darkens the surface of summer snowfields, increasing snowmelt. To assess the contribution of red snow to supraglacial snowmelt in northwestern North America, we systematically mapped the 2019-2022 distribution of blooms by applying supervised classification to 6158 satellite images. Blooms occurred on 5% of the total glaciated area, heavily affecting many glaciers in years of prolonged snow cover duration. Individual glaciers had up to 65% of their surface area affected by bloom in one melt season, which we estimate caused as much as 3 cm of snow meltwater equivalent averaged across the glacier surface. These results demonstrate appreciable snowmelt caused by red snow albedo over vast areas of North American glaciers.
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Affiliation(s)
- Casey B. Engstrom
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
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2
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van Hees D, Hanneman C, Paradis S, Camara AG, Matsumoto M, Hamilton T, Krueger-Hadfield SA, Kodner RB. Patchy and Pink: Dynamics of a Chlainomonas sp. (Chlamydomonadales, chlorophyta) algal bloom on Bagley Lake, North Cascades, WA. FEMS Microbiol Ecol 2023; 99:fiad106. [PMID: 37675994 PMCID: PMC10580270 DOI: 10.1093/femsec/fiad106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/18/2023] [Accepted: 09/06/2023] [Indexed: 09/08/2023] Open
Abstract
Snow algal blooms frequently occur throughout alpine and polar environments during spring and summer months; however, our understanding of bloom dynamics is limited. We tracked a recurrent bloom of Chlainomonas sp. on Upper Bagley Lake in the North Cascade Mountains, USA, to assess the spatiotemporal dynamics in bloom color intensity, community photophysiology, and community composition over eight weeks. We found that the algae biomass had a dynamic patchy distribution over space and time, which was decoupled from changes in community composition and life-cycle progress averaged across the bloom. The proportional representation of Chlainomonas sp. remained consistent throughout the study while the overall community composition shows a progression through the bloom. We found that community photophysiology, measured by the maximum quantum yield of PSII (Fv/Fm), decreased on average throughout the bloom. These findings suggest that the Chlainomonas sp. community on Bagley Lake is not simply an algal bloom with rapid increase in biomass followed by a population crash, as is often seen in aquatic systems, though there is a physiological trajectory and sensitivity to environmental stress. These results contribute to our understanding of the biology of Chlainomonas sp. and its response to environmental stress, specifically an extreme warming event.
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Affiliation(s)
- Dan van Hees
- Biology Department, Western Washington University, Bellingham, WA 98225, United States
| | - Clare Hanneman
- Biology Department, Western Washington University, Bellingham, WA 98225, United States
| | - Sophie Paradis
- Biology Department, Western Washington University, Bellingham, WA 98225, United States
| | - A G Camara
- Biology Department, Western Washington University, Bellingham, WA 98225, United States
| | - Maya Matsumoto
- Biology Department, Western Washington University, Bellingham, WA 98225, United States
| | - Trinity Hamilton
- Department of Plant and Microbial Biology and the BioTechnology Institute, University of Minnesota
St. Paul, MN 55108, United States
| | - Stacy A Krueger-Hadfield
- Department of Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Robin B Kodner
- Environmental Science, Western Washington University, Bellingham, WA 98225, United States
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3
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Huang H, Qian Y, He C, Bair EH, Rittger K. Snow Albedo Feedbacks Enhance Snow Impurity-Induced Radiative Forcing in the Sierra Nevada. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2022GL098102. [PMID: 35859851 PMCID: PMC9285762 DOI: 10.1029/2022gl098102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/26/2022] [Accepted: 05/15/2022] [Indexed: 06/15/2023]
Abstract
This study employs a fully coupled meteorology-chemistry-snow model to investigate the impacts of light-absorbing particles (LAPs) on snow darkening in the Sierra Nevada. After comprehensive evaluation with spatially and temporally complete satellite retrievals, the model shows that LAPs in snow reduce snow albedo by 0.013 (0-0.045) in the Sierra Nevada during the ablation season (April-July), producing a midday mean radiative forcing of 4.5 W m-2 which increases to 15-22 W m-2 in July. LAPs in snow accelerate snow aging processes and reduce snow cover fraction, which doubles the albedo change and radiative forcing caused by LAPs. The impurity-induced snow darkening effects decrease snow water equivalent and snow depth by 20 and 70 mm in June in the Sierra Nevada bighorn sheep habitat. The earlier snowmelt reduces root-zone soil water content by 20%, deteriorating the forage productivity and playing a negative role in the survival of bighorn sheep.
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Affiliation(s)
- Huilin Huang
- Pacific Northwest National LaboratoryAtmospheric Sciences and Global Change DivisionRichlandWAUSA
| | - Yun Qian
- Pacific Northwest National LaboratoryAtmospheric Sciences and Global Change DivisionRichlandWAUSA
| | - Cenlin He
- Research Applications LaboratoryNational Center for Atmospheric ResearchBoulderCOUSA
| | - Edward H. Bair
- Earth Research InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Karl Rittger
- Institute for Arctic and Alpine ResearchUniversity of Colorado BoulderBoulderCOUSA
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4
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Fonseca EL, Santos ECD, Figueiredo ARDE, Simões JC. Antarctic biological soil crusts surface reflectance patterns from landsat and sentinel-2 images. AN ACAD BRAS CIENC 2022; 94:e20210596. [PMID: 35544838 DOI: 10.1590/0001-3765202220210596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 11/10/2021] [Indexed: 11/21/2022] Open
Abstract
The remote sensing techniques must be used to obtain long-term information in remote areas, like the Antarctic continent, to monitor the environmental productivity and its changes. The aim of this work was to analyze the surface reflectance profile patterns for the Antarctic biological soil crusts (algae, lichens, and mosses) in an area of Nelson Island (South Shetland Islands, maritime Antarctic), calculated from Landsat and Sentinel-2 images to identify its similarities and differences due to targets, sensors and acquired date. The surface reflectance values for Antarctic biological soil crusts are similar for those observed for biological soil crusts in other Earth extreme environments, like deserts. In Landsat images, the differences among biological soil crusts surface reflectance were identified at visible and near-infrared wavelengths and for Sentinel-2 images, the differences occur at visible, red-edge and shortwave infrared wavelengths, showing the feasibility of using surface reflectance products to identify these different crusts, despite its inherent pixel spectral mixture. Long-term biophysical parameters from such crusts as retrieved from orbital data is not possible due to very low cloud-free images over the Antarctic, which prevents building a consistent surface reflectance time-series which covers all biological soil crusts growth season.
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Affiliation(s)
- Eliana L Fonseca
- Universidade Federal do Rio Grande do Sul, Centro Polar e Climático, Departament of Geography, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil
| | - Edvan C Dos Santos
- Universidade Federal do Rio Grande do Sul, Centro Polar e Climático, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil
| | - Anderson R DE Figueiredo
- Universidade Federal do Rio Grande do Sul, Centro Polar e Climático, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil
| | - Jefferson C Simões
- Universidade Federal do Rio Grande do Sul, Centro Polar e Climático, Departament of Geography, Av. Bento Gonçalves, 9500, 91501-970 Porto Alegre, RS, Brazil.,University of Maine, Climate Change Institute, Bryand Global Sciences Building, 04469-5790, Orono, ME, USA
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5
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Coelho LF, Madden J, Kaltenegger L, Zinder S, Philpot W, Esquível MG, Canário J, Costa R, Vincent WF, Martins Z. Color Catalogue of Life in Ice: Surface Biosignatures on Icy Worlds. ASTROBIOLOGY 2022; 22:313-321. [PMID: 34964651 DOI: 10.1089/ast.2021.0008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
With thousands of discovered planets orbiting other stars and new missions that will explore our solar system, the search for life in the universe has entered a new era. However, a reference database to enable our search for life on the surface of icy exoplanets and exomoons by using records from Earth's icy biota is missing. Therefore, we developed a spectra catalogue of life in ice to facilitate the search for extraterrestrial signs of life. We measured the reflection spectra of 80 microorganisms-with a wide range of pigments-isolated from ice and water. We show that carotenoid signatures are wide-ranged and intriguing signs of life. Our measurements allow for the identification of such surface life on icy extraterrestrial environments in preparation for observations with the upcoming ground- and space-based telescopes. Dried samples reveal even higher reflectance, which suggests that signatures of surface biota could be more intense on exoplanets and moons that are drier than Earth or on environments like Titan where potential life-forms may use a different solvent. Our spectra library covers the visible to near-infrared and is available online. It provides a guide for the search for surface life on icy worlds based on biota from Earth's icy environments.
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Affiliation(s)
- Lígia F Coelho
- Centro de Química Estrutural, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
- Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Jack Madden
- Department of Astronomy, Cornell University, Ithaca, New York, USA
- Carl Sagan Institute, Ithaca, New York, USA
| | - Lisa Kaltenegger
- Department of Astronomy, Cornell University, Ithaca, New York, USA
- Carl Sagan Institute, Ithaca, New York, USA
| | - Stephen Zinder
- Carl Sagan Institute, Ithaca, New York, USA
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - William Philpot
- Carl Sagan Institute, Ithaca, New York, USA
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York, USA
| | - M Glória Esquível
- Landscape, Environment, Agriculture and Food-LEAF Centre, Instituto Superior de Agronomia, Universidade de Lisboa, Lisboa, Portugal
| | - João Canário
- Centro de Química Estrutural, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Rodrigo Costa
- Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Warwick F Vincent
- Centre for Northern Studies (CEN), Takuvik & Biology Department, Université Laval, Québec, Canada
| | - Zita Martins
- Centro de Química Estrutural, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
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Cycil LM, Hausrath EM, Ming DW, Adcock CT, Raymond J, Remias D, Ruemmele WP. Investigating the Growth of Algae Under Low Atmospheric Pressures for Potential Food and Oxygen Production on Mars. Front Microbiol 2021; 12:733244. [PMID: 34867849 PMCID: PMC8633435 DOI: 10.3389/fmicb.2021.733244] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
With long-term missions to Mars and beyond that would not allow resupply, a self-sustaining Bioregenerative Life Support System (BLSS) is essential. Algae are promising candidates for BLSS due to their completely edible biomass, fast growth rates and ease of handling. Extremophilic algae such as snow algae and halophilic algae may also be especially suited for a BLSS because of their ability to grow under extreme conditions. However, as indicated from over 50 prior space studies examining algal growth, little is known about the growth of algae at close to Mars-relevant pressures. Here, we explored the potential for five algae species to produce oxygen and food under low-pressure conditions relevant to Mars. These included Chloromonas brevispina, Kremastochrysopsis austriaca, Dunaliella salina, Chlorella vulgaris, and Spirulina plantensis. The cultures were grown in duplicate in a low-pressure growth chamber at 670 ± 20 mbar, 330 ± 20 mbar, 160 ± 20 mbar, and 80 ± 2.5 mbar pressures under continuous light exposure (62-70 μmol m-2 s-1). The atmosphere was evacuated and purged with CO2 after sampling each week. Growth experiments showed that D. salina, C. brevispina, and C. vulgaris were the best candidates to be used for BLSS at low pressure. The highest carrying capacities for each species under low pressure conditions were achieved by D. salina at 160 mbar (30.0 ± 4.6 × 105 cells/ml), followed by C. brevispina at 330 mbar (19.8 ± 0.9 × 105 cells/ml) and C. vulgaris at 160 mbar (13.0 ± 1.5 × 105 cells/ml). C. brevispina, D. salina, and C. vulgaris all also displayed substantial growth at the lowest tested pressure of 80 mbar reaching concentrations of 43.4 ± 2.5 × 104, 15.8 ± 1.3 × 104, and 57.1 ± 4.5 × 104 cells per ml, respectively. These results indicate that these species are promising candidates for the development of a Mars-based BLSS using low pressure (∼200-300 mbar) greenhouses and inflatable structures that have already been conceptualized and designed.
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Affiliation(s)
- Leena M Cycil
- Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Elisabeth M Hausrath
- Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | | | - Christopher T Adcock
- Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - James Raymond
- School of Life Sciences, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Daniel Remias
- School of Engineering, University of Applied Sciences Upper Austria, Wels, Austria
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7
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Optical, Geochemical and Mineralogical Characteristics of Light-Absorbing Impurities Deposited on Djankuat Glacier in the Caucasus Mountains. WATER 2021. [DOI: 10.3390/w13212993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Supra-glacial material, including light-absorbing impurities (LAI) such as mineral dust of crustal and soil origin, black carbon, algae and cryoconite, reduce the reflectance of snow and glacier ice. The reduction depends on the amount of LAI and their physical and chemical properties, which vary spatially and temporally. Spectral reflectance data and snow and ice samples, containing LAI, were collected in the ablation zone of the Djankuat Glacier, Central Caucasus, Russia. The spectra of the samples containing mineral dust transported from deserts were characterized by negative visible near-infrared gradients and were different from the spectra of clean aged snow and exposed glacier ice and from the samples containing mineral dust produced locally. Geochemical and mineralogical analysis using X-ray diffraction and X-ray fluorescence spectrometry showed that samples containing desert dust were characterised by a high proportion of clay materials and such minerals as smectites, illite–smectites and palygorskite and by a smaller size of mineral particles. They were enriched in chromium, zinc and vanadium. The latter served as an indicator of dust transport over or origin from the oil-producing regions of the Middle East. There was a strong negative correlation between the amount of organic matter and mineral dust in the collected samples and the albedo of surfaces from which the samples were collected. The results suggested that organic matter reduced albedo more efficiently than mineral dust. The study highlighted the importance of supra-glacial material in changing the surface reflectivity of snow and glaciers in the Caucasus region.
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8
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Gray A, Krolikowski M, Fretwell P, Convey P, Peck LS, Mendelova M, Smith AG, Davey MP. Remote Sensing Phenology of Antarctic Green and Red Snow Algae Using WorldView Satellites. FRONTIERS IN PLANT SCIENCE 2021; 12:671981. [PMID: 34226827 PMCID: PMC8254402 DOI: 10.3389/fpls.2021.671981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/20/2021] [Indexed: 06/13/2023]
Abstract
Snow algae are an important group of terrestrial photosynthetic organisms in Antarctica, where they mostly grow in low lying coastal snow fields. Reliable observations of Antarctic snow algae are difficult owing to the transient nature of their blooms and the logistics involved to travel and work there. Previous studies have used Sentinel 2 satellite imagery to detect and monitor snow algal blooms remotely, but were limited by the coarse spatial resolution and difficulties detecting red blooms. Here, for the first time, we use high-resolution WorldView multispectral satellite imagery to study Antarctic snow algal blooms in detail, tracking the growth of red and green blooms throughout the summer. Our remote sensing approach was developed alongside two Antarctic field seasons, where field spectroscopy was used to build a detection model capable of estimating cell density. Global Positioning System (GPS) tagging of blooms and in situ life cycle analysis was used to validate and verify our model output. WorldView imagery was then used successfully to identify red and green snow algae on Anchorage Island (Ryder Bay, 67°S), estimating peak coverage to be 9.48 × 104 and 6.26 × 104 m2, respectively. Combined, this was greater than terrestrial vegetation area coverage for the island, measured using a normalized difference vegetation index. Green snow algae had greater cell density and average layer thickness than red blooms (6.0 × 104 vs. 4.3 × 104 cells ml-1) and so for Anchorage Island we estimated that green algae dry biomass was over three times that of red algae (567 vs. 180 kg, respectively). Because the high spatial resolution of the WorldView imagery and its ability to detect red blooms, calculated snow algal area was 17.5 times greater than estimated with Sentinel 2 imagery. This highlights a scaling problem of using coarse resolution imagery and suggests snow algal contribution to net primary productivity on Antarctica may be far greater than previously recognized.
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Affiliation(s)
- Andrew Gray
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- Field Spectroscopy Facility (Natural Environment Research Council), University of Edinburgh, Edinburgh, United Kingdom
| | - Monika Krolikowski
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Peter Fretwell
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Peter Convey
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Lloyd S. Peck
- British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
| | - Monika Mendelova
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Alison G. Smith
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Matthew P. Davey
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
- The Scottish Association for Marine Science, Oban, United Kingdom
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9
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Zheng Y, Xue C, Chen H, He C, Wang Q. Low-Temperature Adaptation of the Snow Alga Chlamydomonas nivalis Is Associated With the Photosynthetic System Regulatory Process. Front Microbiol 2020; 11:1233. [PMID: 32587584 PMCID: PMC7297934 DOI: 10.3389/fmicb.2020.01233] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 05/14/2020] [Indexed: 12/28/2022] Open
Abstract
The alga Chlamydomonas nivalis thrives in polar snow fields and on high-altitude mountain tops, and contributes significantly on primary production in the polar regions, however, the mechanisms underlying this adaptation to low temperatures are unknown. Here, we compared the growth, photosynthetic activity, membrane lipid peroxidation, and antioxidant activity of C. nivalis with those of the model alga C. reinhardtii, under grow temperature and low temperatures. C. nivalis maintained its photosynthetic activity in these conditions by reducing the light-harvesting ability of photosystem II and enhancing the cyclic electron transfer around photosystem I, both of which limited damage to the photosystem from excess light energy and resulted in ATP production, supporting cellular growth and other physiological processes. Furthermore, the increased cyclic electron transfer rate, carotenoid content, and antioxidant enzyme activities jointly regulated the reactive oxygen species levels in C. nivalis, enabling recovery from excess excitation energy and reduced photooxidative damage to the cell. Therefore, we propose a model in which adaptive mechanisms related to photosynthetic regulation promote the survival and even blooming of C. nivalis under polar environment, suggesting that C. nivalis can provide organic carbon sources as an important primary producer for other surrounding life in the polar regions for maintaining ecosystem.
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Affiliation(s)
- Yanli Zheng
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Chunling Xue
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Hui Chen
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China
| | - Chenliu He
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, China.,Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan, China
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10
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Gray A, Krolikowski M, Fretwell P, Convey P, Peck LS, Mendelova M, Smith AG, Davey MP. Remote sensing reveals Antarctic green snow algae as important terrestrial carbon sink. Nat Commun 2020; 11:2527. [PMID: 32433543 PMCID: PMC7239900 DOI: 10.1038/s41467-020-16018-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 04/02/2020] [Indexed: 12/25/2022] Open
Abstract
We present the first estimate of green snow algae community biomass and distribution along the Antarctic Peninsula. Sentinel 2 imagery supported by two field campaigns revealed 1679 snow algae blooms, seasonally covering 1.95 × 106 m2 and equating to 1.3 × 103 tonnes total dry biomass. Ecosystem range is limited to areas with average positive summer temperatures, and distribution strongly influenced by marine nutrient inputs, with 60% of blooms less than 5 km from a penguin colony. A warming Antarctica may lose a majority of the 62% of blooms occupying small, low-lying islands with no high ground for range expansion. However, bloom area and elevation were observed to increase at lower latitudes, suggesting that parallel expansion of bloom area on larger landmasses, close to bird or seal colonies, is likely. This increase is predicted to outweigh biomass lost from small islands, resulting in a net increase in snow algae extent and biomass as the Peninsula warms. Snow algae bloom along the coast of Antarctica and are likely to be biogeochemically important. Here, the authors produced the first map of such blooms, show that they are driven by warmer temperatures and proximity to birds and mammals, and are likely to increase given projected climate changes.
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Affiliation(s)
- Andrew Gray
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK. .,NERC Field Spectroscopy Facility, Edinburgh, EH3 9FE, UK.
| | - Monika Krolikowski
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Peter Fretwell
- British Antarctic Survey, NERC, Madingley Road, Cambridge, CB3 0ET, UK
| | - Peter Convey
- British Antarctic Survey, NERC, Madingley Road, Cambridge, CB3 0ET, UK
| | - Lloyd S Peck
- British Antarctic Survey, NERC, Madingley Road, Cambridge, CB3 0ET, UK
| | - Monika Mendelova
- University of Edinburgh, School of GeoSciences, Edinburgh, EH8 9XP, UK
| | - Alison G Smith
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Matthew P Davey
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK.
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11
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Edwards A, Cameron KA, Cook JM, Debbonaire AR, Furness E, Hay MC, Rassner SM. Microbial genomics amidst the Arctic crisis. Microb Genom 2020; 6:e000375. [PMID: 32392124 PMCID: PMC7371112 DOI: 10.1099/mgen.0.000375] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 04/16/2020] [Indexed: 12/16/2022] Open
Abstract
The Arctic is warming - fast. Microbes in the Arctic play pivotal roles in feedbacks that magnify the impacts of Arctic change. Understanding the genome evolution, diversity and dynamics of Arctic microbes can provide insights relevant for both fundamental microbiology and interdisciplinary Arctic science. Within this synthesis, we highlight four key areas where genomic insights to the microbial dimensions of Arctic change are urgently required: the changing Arctic Ocean, greenhouse gas release from the thawing permafrost, 'biological darkening' of glacial surfaces, and human activities within the Arctic. Furthermore, we identify four principal challenges that provide opportunities for timely innovation in Arctic microbial genomics. These range from insufficient genomic data to develop unifying concepts or model organisms for Arctic microbiology to challenges in gaining authentic insights to the structure and function of low-biomass microbiota and integration of data on the causes and consequences of microbial feedbacks across scales. We contend that our insights to date on the genomics of Arctic microbes are limited in these key areas, and we identify priorities and new ways of working to help ensure microbial genomics is in the vanguard of the scientific response to the Arctic crisis.
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Affiliation(s)
- Arwyn Edwards
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Karen A. Cameron
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Joseph M. Cook
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Aliyah R. Debbonaire
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Eleanor Furness
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Melanie C. Hay
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
| | - Sara M.E. Rassner
- Interdisciplinary Centre for Environmental Microbiology, Institute of Biological, Environmental and Rural Sciences, Cledwyn Building, Aberystwyth University, Cymru SY23 3DD, UK
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12
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An Interaction Methodology to Collect and Assess User-Driven Requirements to Define Potential Opportunities of Future Hyperspectral Imaging Sentinel Mission. REMOTE SENSING 2020. [DOI: 10.3390/rs12081286] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Evolution in the Copernicus Space Component is foreseen in the mid-2020s to meet priority user needs not addressed by the existing infrastructure, and/or to reinforce existing services. In this context, the European Commission is intending to evaluate the overall potential utility of a complementary Copernicus hyperspectral mission to be added to the Copernicus Sentinels fleet. Hyperspectral imaging is a powerful remote sensing technology that, allowing the characterization and quantification of Earth surface materials, has the potential to deliver significant enhancements in quantitative value-added products. This study aims to illustrate the interaction methodology that was set up to collect and assess user-driven requirements in different thematic areas to demonstrate the potential benefit of a future Copernicus hyperspectral mission. Therefore, an ad hoc interaction matrix was circulated among several user communities to gather preferences about hyperspectral-based products and services. The results show how the involvement of several user communities strengthens the identification of these user requirements. Moreover, the requirement evaluation is used to identify potential opportunities of hyperspectral imaging in addressing operational needs associated with policy obligations at European, national, and local levels. The frequency distribution of spectral range classes and spatial and temporal resolutions are also derived from the preference expressed by the user communities in each thematic area investigated.
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Glacier algae foster ice-albedo feedback in the European Alps. Sci Rep 2020; 10:4739. [PMID: 32179790 PMCID: PMC7075879 DOI: 10.1038/s41598-020-61762-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/18/2020] [Indexed: 01/25/2023] Open
Abstract
The melting of glaciers and ice sheets is nowadays considered a symbol of climate change. Many complex mechanisms are involved in the melting of ice, and, among these processes, surface darkening due to organic material on bare ice has recently received attention from the scientific community. The presence of microbes on glaciers has been shown to decrease the albedo of ice and promote melting. Despite several studies from the Himalaya, Greenland, Andes, and Alaska, no quantitative studies have yet been conducted in the European Alps. In this paper, we made use of DNA sequencing, microscopy and field spectroscopy to describe the nature of glacier algae found at a glacier (Vadret da Morteratsch) of the European Alps and to evaluate their effect on the ice-albedo feedback. Among different algal species identified in the samples, we found a remarkable abundance of Ancylonema nordenskioeldii, a species that has never previously been quantitatively documented in the Alps and that dominates algal blooms on the Greenland Ice Sheet. Our results show that, at the end of the ablation season, the concentration of Ancylonema nordenskioeldii on the glacier surface is higher than that of other algal species (i.e. Mesotaenium berggrenii). Using field spectroscopy data, we identified a significant correlation between a reflectance ratio (750 nm/650 nm) and the algae concentration. This reflectance ratio could be useful for future mapping of glacier algae from remote sensing data exploiting band 6 (740 nm) and band 4 (665 nm) of the MultiSpectral Instrument (MSI) on board Sentinel-2 satellite. Here we show that the biological darkening of glaciers (i.e. the bioalbedo feedback) is also occurring in the European Alps, and thus it is a global process that must be taken into account when considering the positive feedback mechanisms related to glacier melting.
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Satellite Remote Sensing of the Greenland Ice Sheet Ablation Zone: A Review. REMOTE SENSING 2019. [DOI: 10.3390/rs11202405] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Greenland Ice Sheet is now the largest land ice contributor to global sea level rise, largely driven by increased surface meltwater runoff from the ablation zone, i.e., areas of the ice sheet where annual mass losses exceed gains. This small but critically important area of the ice sheet has expanded in size by ~50% since the early 1960s, and satellite remote sensing is a powerful tool for monitoring the physical processes that influence its surface mass balance. This review synthesizes key remote sensing methods and scientific findings from satellite remote sensing of the Greenland Ice Sheet ablation zone, covering progress in (1) radar altimetry, (2) laser (lidar) altimetry, (3) gravimetry, (4) multispectral optical imagery, and (5) microwave and thermal imagery. Physical characteristics and quantities examined include surface elevation change, gravimetric mass balance, reflectance, albedo, and mapping of surface melt extent and glaciological facies and zones. The review concludes that future progress will benefit most from methods that combine multi-sensor, multi-wavelength, and cross-platform datasets designed to discriminate the widely varying surface processes in the ablation zone. Specific examples include fusing laser altimetry, radar altimetry, and optical stereophotogrammetry to enhance spatial measurement density, cross-validate surface elevation change, and diagnose radar elevation bias; employing dual-frequency radar, microwave scatterometry, or combining radar and laser altimetry to map seasonal snow depth; fusing optical imagery, radar imagery, and microwave scatterometry to discriminate between snow, liquid water, refrozen meltwater, and bare ice near the equilibrium line altitude; combining optical reflectance with laser altimetry to map supraglacial lake, stream, and crevasse bathymetry; and monitoring the inland migration of snowlines, surface melt extent, and supraglacial hydrologic features.
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15
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Williamson CJ, Cameron KA, Cook JM, Zarsky JD, Stibal M, Edwards A. Glacier Algae: A Dark Past and a Darker Future. Front Microbiol 2019; 10:524. [PMID: 31019491 PMCID: PMC6458304 DOI: 10.3389/fmicb.2019.00524] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/28/2019] [Indexed: 11/13/2022] Open
Abstract
"Glacier algae" grow on melting glacier and ice sheet surfaces across the cryosphere, causing the ice to absorb more solar energy and consequently melt faster, while also turning over carbon and nutrients. This makes glacier algal assemblages, which are typically dominated by just three main species, a potentially important yet under-researched component of the global biosphere, carbon, and water cycles. This review synthesizes current knowledge on glacier algae phylogenetics, physiology, and ecology. We discuss their significance for the evolution of early land plants and highlight their impacts on the physical and chemical supraglacial environment including their role as drivers of positive feedbacks to climate warming, thereby demonstrating their influence on Earth's past and future. Four complementary research priorities are identified, which will facilitate broad advances in glacier algae research, including establishment of reliable culture collections, sequencing of glacier algae genomes, development of diagnostic biosignatures for remote sensing, and improved predictive modeling of glacier algae biological-albedo effects.
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Affiliation(s)
- Christopher J Williamson
- Bristol Glaciology Centre, School of Geographical Sciences, University of Bristol, Bristol, United Kingdom
| | - Karen A Cameron
- Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Joseph M Cook
- Department of Geography, The University of Sheffield, Sheffield, United Kingdom
| | - Jakub D Zarsky
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Marek Stibal
- Department of Ecology, Faculty of Science, Charles University, Prague, Czechia
| | - Arwyn Edwards
- Institute of Biological, Environmental & Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
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Dial RJ, Ganey GQ, Skiles SM. What color should glacier algae be? An ecological role for red carbon in the cryosphere. FEMS Microbiol Ecol 2019; 94:4810544. [PMID: 29346532 DOI: 10.1093/femsec/fiy007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/12/2018] [Indexed: 11/13/2022] Open
Abstract
Red-colored secondary pigments in glacier algae play an adaptive role in melting snow and ice. We advance this hypothesis using a model of color-based absorption of irradiance, an experiment with colored particles in snow, and the natural history of glacier algae. Carotenoids and phenols-astaxanthin in snow-algae and purpurogallin in ice-algae-shield photosynthetic apparatus by absorbing overabundant visible wavelengths, then dissipating the excess radiant energy as heat. This heat melts proximal ice crystals, providing liquid-water in a 0°C environment and freeing up nutrients bound in frozen water. We show that purple-colored particles transfer 87%-89% of solar energy absorbed by black particles. However, red-colored particles transfer nearly as much (85%-87%) by absorbing peak solar wavelengths and reflecting the visible wavelengths most absorbed by nearby ice and snow crystals; this latter process may reduce potential cellular overheating when snow insulates cells. Blue and green particles transfer only 80%-82% of black particle absorption. In the experiment, red-colored particles melted 87% as much snow as black particles, while blue particles melted 77%. Green-colored snow-algae naturally occupy saturated snow where water is non-limiting; red-colored snow-algae occupy drier, water-limited snow. In addition to increasing melt, we suggest that esterified astaxanthin in snow-alga cells increases hydrophobicity to remain surficial.
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Affiliation(s)
- Roman J Dial
- Institute of Culture and Environment, Alaska Pacific University, 4101 University Drive, Anchorage, AK 99508, USA
| | - Gerard Q Ganey
- Institute of Culture and Environment, Alaska Pacific University, 4101 University Drive, Anchorage, AK 99508, USA
| | - S McKenzie Skiles
- Department of Geography, University of Utah, 332 S 1400 E, Salt Lake City, UT 84112, USA
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17
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Abstract
Oxygenic photosynthesis is Earth's dominant metabolism, having evolved to harvest the largest expected energy source at the surface of most terrestrial habitable zone planets. Using CO2 and H2O-molecules that are expected to be abundant and widespread on habitable terrestrial planets-oxygenic photosynthesis is plausible as a significant planetary process with a global impact. Photosynthetic O2 has long been considered particularly robust as a sign of life on a habitable exoplanet, due to the lack of known "false positives"-geological or photochemical processes that could also produce large quantities of stable O2. O2 has other advantages as a biosignature, including its high abundance and uniform distribution throughout the atmospheric column and its distinct, strong absorption in the visible and near-infrared. However, recent modeling work has shown that false positives for abundant oxygen or ozone could be produced by abiotic mechanisms, including photochemistry and atmospheric escape. Environmental factors for abiotic O2 have been identified and will improve our ability to choose optimal targets and measurements to guard against false positives. Most of these false-positive mechanisms are dependent on properties of the host star and are often strongest for planets orbiting M dwarfs. In particular, selecting planets found within the conservative habitable zone and those orbiting host stars more massive than 0.4 M⊙ (M3V and earlier) may help avoid planets with abundant abiotic O2 generated by water loss. Searching for O4 or CO in the planetary spectrum, or the lack of H2O or CH4, could help discriminate between abiotic and biological sources of O2 or O3. In advance of the next generation of telescopes, thorough evaluation of potential biosignatures-including likely environmental context and factors that could produce false positives-ultimately works to increase our confidence in life detection. Key Words: Biosignatures-Exoplanets-Oxygen-Photosynthesis-Planetary spectra. Astrobiology 17, 1022-1052.
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Affiliation(s)
- Victoria S Meadows
- 1 Department of Astronomy and Astrobiology Program, University of Washington , Seattle, Washington
- 2 NASA Astrobiology Institute-Virtual Planetary Laboratory , USA
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18
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The biogeography of red snow microbiomes and their role in melting arctic glaciers. Nat Commun 2016; 7:11968. [PMID: 27329445 PMCID: PMC4917964 DOI: 10.1038/ncomms11968] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 05/17/2016] [Indexed: 11/08/2022] Open
Abstract
The Arctic is melting at an unprecedented rate and key drivers are changes in snow
and ice albedo. Here we show that red snow, a common algal habitat blooming after
the onset of melting, plays a crucial role in decreasing albedo. Our data reveal
that red pigmented snow algae are cosmopolitan as well as independent of
location-specific geochemical and mineralogical factors. The patterns for snow algal
diversity, pigmentation and, consequently albedo, are ubiquitous across the Arctic
and the reduction in albedo accelerates snow melt and increases the time and area of
exposed bare ice. We estimated that the overall decrease in snow albedo by red
pigmented snow algal blooms over the course of one melt season can be
13%. This will invariably result in higher melt rates. We argue that such
a ‘bio-albedo' effect has to be considered in climate
models. The Arctic is melting at an unprecedented rate and key drivers are
changes in snow and ice albedo. Here, the authors show that red pigmented snow algae
play a crucial role in decreasing surface albedo and their patterns for diversity,
pigmentation, and consequently albedo, are ubiquitous across the Arctic.
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Schwieterman EW, Cockell CS, Meadows VS. Nonphotosynthetic pigments as potential biosignatures. ASTROBIOLOGY 2015; 15:341-61. [PMID: 25941875 PMCID: PMC4442567 DOI: 10.1089/ast.2014.1178] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Previous work on possible surface reflectance biosignatures for Earth-like planets has typically focused on analogues to spectral features produced by photosynthetic organisms on Earth, such as the vegetation red edge. Although oxygenic photosynthesis, facilitated by pigments evolved to capture photons, is the dominant metabolism on our planet, pigmentation has evolved for multiple purposes to adapt organisms to their environment. We present an interdisciplinary study of the diversity and detectability of nonphotosynthetic pigments as biosignatures, which includes a description of environments that host nonphotosynthetic biologically pigmented surfaces, and a lab-based experimental analysis of the spectral and broadband color diversity of pigmented organisms on Earth. We test the utility of broadband color to distinguish between Earth-like planets with significant coverage of nonphotosynthetic pigments and those with photosynthetic or nonbiological surfaces, using both 1-D and 3-D spectral models. We demonstrate that, given sufficient surface coverage, nonphotosynthetic pigments could significantly impact the disk-averaged spectrum of a planet. However, we find that due to the possible diversity of organisms and environments, and the confounding effects of the atmosphere and clouds, determination of substantial coverage by biologically produced pigments would be difficult with broadband colors alone and would likely require spectrally resolved data.
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Affiliation(s)
- Edward W. Schwieterman
- University of Washington Astronomy Department, Seattle, Washington, USA
- NAI Virtual Planetary Laboratory, Seattle, Washington, USA
- University of Washington Astrobiology Program, Seattle, Washington, USA
| | - Charles S. Cockell
- University of Edinburgh School of Physics and Astronomy, Edinburgh, UK
- UK Centre for Astrobiology, Edinburgh, UK
| | - Victoria S. Meadows
- University of Washington Astronomy Department, Seattle, Washington, USA
- NAI Virtual Planetary Laboratory, Seattle, Washington, USA
- University of Washington Astrobiology Program, Seattle, Washington, USA
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20
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Spijkerman E, Wacker A, Weithoff G, Leya T. Elemental and fatty acid composition of snow algae in Arctic habitats. Front Microbiol 2012; 3:380. [PMID: 23112797 PMCID: PMC3482990 DOI: 10.3389/fmicb.2012.00380] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 10/09/2012] [Indexed: 11/23/2022] Open
Abstract
Red, orange or green snow is the macroscopic phenomenon comprising different eukaryotic algae. Little is known about the ecology and nutrient regimes in these algal communities. Therefore, eight snow algal communities from five intensively tinted snow fields in western Spitsbergen were analysed for nutrient concentrations and fatty acid (FA) composition. To evaluate the importance of a shift from green to red forms on the FA-variability of the field samples, four snow algal strains were grown under nitrogen replete and moderate light (+N+ML) or N-limited and high light (−N+HL) conditions. All eight field algal communities were dominated by red and orange cysts. Dissolved nutrient concentration of the snow revealed a broad range of NH+4 (<0.005–1.2 mg N l−1) and only low PO3−4 (<18 μg P l−1) levels. The external nutrient concentration did not reflect cellular nutrient ratios as C:N and C:P ratios of the communities were highest at locations containing relatively high concentrations of NH+4 and PO3−4. Molar N:P ratios ranged from 11 to 21 and did not suggest clear limitation of a single nutrient. On a per carbon basis, we found a 6-fold difference in total FA content between the eight snow algal communities, ranging from 50 to 300 mg FA g C−1. In multivariate analyses total FA content opposed the cellular N:C quota and a large part of the FA variability among field locations originated from the abundant FAs C18:1n-9, C18:2n-6, and C18:3n-3. Both field samples and snow algal strains grown under −N+HL conditions had high concentrations of C18:1n-9. FAs possibly accumulated due to the cessation of growth. Differences in color and nutritional composition between patches of snow algal communities within one snow field were not directly related to nutrient conditions. We propose that the highly patchy distribution of snow algae within and between snow fields may also result from differences in topographical and geological parameters such as slope, melting water rivulets, and rock formation.
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Affiliation(s)
- Elly Spijkerman
- Department of Ecology and Ecosystem Modelling, University of Potsdam Potsdam, Germany
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21
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Yan P, Hou S, Chen T, Ma X, Zhang S. Culturable bacteria isolated from snow cores along the 1300 km traverse from Zhongshan Station to Dome A, East Antarctica. Extremophiles 2012; 16:345-354. [PMID: 22297697 DOI: 10.1007/s00792-012-0434-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2012] [Accepted: 01/18/2012] [Indexed: 11/27/2022]
Abstract
The abundance and community composition of culturable bacteria in four snow cores along the 1300 km traverse from Zhongshan Station to Dome A, East Antarctica, were investigated through the combination of liquid and solid media and small subunit 16S rRNA sequences. Under aerobic cultivation conditions, the average concentrations of bacterial colonies from each snow core varied from 0.008 to 0.32 CFU mL(-1). A total of 37 and 15 isolates with different morphologic characteristics were recovered from solid and liquid media PYGV, respectively. The phylogenetic analysis of 14 representatives with different ARDRA patterns from RFLP showed that all the isolates were affiliated with five phylogenetic groups: Firmicutes, Actinobacteria, Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. Actinobacteria represented the largest cluster with 43% of strains, and these strains exhibited unique phenotypic properties. The community compositions of culturable bacteria in the four snow cores were distinctly different from each other and the concentrations and community sizes of culturable bacteria along the traverse decreased with increases of latitude, altitude and distance from coast, which likely reflected the different bacterial sources and biogeographies under the different regional climate conditions in the snow cover of East Antarctica.
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Affiliation(s)
- Peiying Yan
- State Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
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22
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Fujii M, Takano Y, Kojima H, Hoshino T, Tanaka R, Fukui M. Microbial community structure, pigment composition, and nitrogen source of red snow in Antarctica. MICROBIAL ECOLOGY 2010; 59:466-75. [PMID: 19847476 PMCID: PMC4261141 DOI: 10.1007/s00248-009-9594-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 09/19/2009] [Indexed: 05/03/2023]
Abstract
"Red snow" refers to red-colored snow, caused by bloom of cold-adapted phototrophs, so-called snow algae. The red snow found in Langhovde, Antarctica, was investigated from several viewpoints. Various sizes of rounded red cells were observed in the red snow samples under microscopy. Pigment analysis demonstrated accumulation of astaxanthin in the red snow. Community structure of microorganisms was analyzed by culture-independent methods. In the analyses of small subunit rRNA genes, several species of green algae, fungus, and various phylotypes of bacteria were detected. The detected bacteria were closely related to psychrophilic or psychrotolerant heterotrophic strains, or sequences detected from low-temperature environments. As predominant lineage of bacteria, members of the genus Hymenobacter were consistently detected from samples obtained in two different years. Nitrogen isotopic compositions analysis indicated that the red snow was significantly 15N-enriched. Based on an estimation of trophic level, it was suggested that primary nitrogen sources of the red snow were supplied from fecal pellet of seabirds including a marine top predator of Antarctica.
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Affiliation(s)
- Masanori Fujii
- />The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, 060-0819 Japan
| | - Yoshinori Takano
- />Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, 237-0061 Japan
| | - Hisaya Kojima
- />The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, 060-0819 Japan
| | - Tamotsu Hoshino
- />Institute for Biological Resources and Function, National Institute of Advanced Industrial Science and Technology, 2-17-2-1 Tsukisamu-Higashi, Toyohira-ku, Sapporo, 062-8517 Japan
| | - Ryouichi Tanaka
- />The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, 060-0819 Japan
| | - Manabu Fukui
- />The Institute of Low Temperature Science, Hokkaido University, Kita-19, Nishi-8, Kita-ku, Sapporo, 060-0819 Japan
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23
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Liu Y, Yao T, Jiao N, Kang S, Xu B, Zeng Y, Huang S, Liu X. Bacterial diversity in the snow over Tibetan Plateau Glaciers. Extremophiles 2009; 13:411-23. [PMID: 19159068 DOI: 10.1007/s00792-009-0227-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Accepted: 12/31/2008] [Indexed: 11/30/2022]
Abstract
Bacterial diversity and cell abundance in the snow of the four glaciers (Guoqu, Zadang, East Rongbuk and Palong No. 4) located in different climatic zones of the Tibetan Plateau were investigated through culture-independent molecular analysis of 16S rRNA gene clone library and flow cytometry approaches. Cell abundance ranged from 0.68 x 10(3) to 720 x 10(3) cells mL(-1), with higher values in the northern glaciers than in the southern ones. Bacterial diversity was unexpectedly high in the snow habitats of the world's highest plateau, with 15 common genera distributed widely among the glaciers. The bacterial diversity in the snow at different glaciers was related to the surrounding environments. The Guoqu Glacier, to the north near the desert zone and with the lowest temperature, preserved more bacteria closely related to a cold environment and soil than the other glaciers. However, in the Palong No. 4 Glacier located in the south warm region around vegetation, most bacteria were phylogenetically related to plant-associated bacteria.
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Affiliation(s)
- Yongqin Liu
- Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS), 100085, Beijing, China.
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24
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Hodson A, Anesio AM, Tranter M, Fountain A, Osborn M, Priscu J, Laybourn-Parry J, Sattler B. GLACIAL ECOSYSTEMS. ECOL MONOGR 2008. [DOI: 10.1890/07-0187.1] [Citation(s) in RCA: 382] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Komárek J, Nedbalová L. Green Cryosestic Algae. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2007. [DOI: 10.1007/978-1-4020-6112-7_17] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Brehm-Stecher BF, Johnson EA. Single-cell microbiology: tools, technologies, and applications. Microbiol Mol Biol Rev 2004; 68:538-59, table of contents. [PMID: 15353569 PMCID: PMC515252 DOI: 10.1128/mmbr.68.3.538-559.2004] [Citation(s) in RCA: 297] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The field of microbiology has traditionally been concerned with and focused on studies at the population level. Information on how cells respond to their environment, interact with each other, or undergo complex processes such as cellular differentiation or gene expression has been obtained mostly by inference from population-level data. Individual microorganisms, even those in supposedly "clonal" populations, may differ widely from each other in terms of their genetic composition, physiology, biochemistry, or behavior. This genetic and phenotypic heterogeneity has important practical consequences for a number of human interests, including antibiotic or biocide resistance, the productivity and stability of industrial fermentations, the efficacy of food preservatives, and the potential of pathogens to cause disease. New appreciation of the importance of cellular heterogeneity, coupled with recent advances in technology, has driven the development of new tools and techniques for the study of individual microbial cells. Because observations made at the single-cell level are not subject to the "averaging" effects characteristic of bulk-phase, population-level methods, they offer the unique capacity to observe discrete microbiological phenomena unavailable using traditional approaches. As a result, scientists have been able to characterize microorganisms, their activities, and their interactions at unprecedented levels of detail.
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Affiliation(s)
- Byron F Brehm-Stecher
- Department of Food Microbiology and Toxicology, University of Wisconsin-Madison Food Research Institute, 1925 Willow Drive, Madison, WI 53706, USA
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Abstract
Permanent snow and ice cover great portions of the Arctic and the Antarctic. It appears in winter months in northern parts of America, Asia, and Europe. Therefore snow is an important component of the hydrological cycle. Also, it is a main regulator of the seasonal variation of the planetary albedo. This seasonal change in albedo is determined largely by the snow cover. However, the presence of pollutants and the microstructure of snow (e.g., the size and shape of grains, which depend also on temperature and on the age of the snow) are also of importance in the variation of the snow's spectral albedo. The snow's spectral albedo and its bidirectional reflectance are studied theoretically. The albedo also determines the spectral absorptance of snow, which is of importance, e.g., in studies of the heating regime in snow. We investigate the influence of the nonspherical shape of grains and of close-packed effects on snow's reflectance in the visible and the near-infrared regions of the electromagnetic spectrum. The rate of the spectral transition from highly reflective snow in the visible to almost totally absorbing black snow in the infrared is governed largely by the snow's grain sizes and by the load of pollutants. Therefore both the characteristics of snow and its concentration of impurities can be monitored on a global scale by use of spectrometers and radiometers placed on orbiting satellites.
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Affiliation(s)
- Alexander A Kokhanovsky
- Institute of Environmental Physics, Bremen University, Otto Hahn Allee 1, D-28213 Bremen, Germany.
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Williams WE, Gorton HL, Vogelmann TC. Surface gas-exchange processes of snow algae. Proc Natl Acad Sci U S A 2003; 100:562-6. [PMID: 12518048 PMCID: PMC141035 DOI: 10.1073/pnas.0235560100] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The red-colored chlorophyte Chlamydomonas nivalis is commonly found in summer snowfields. We used a modified Li-Cor gas-exchange system to investigate surface gas-exchange characteristics of snow colonized by this alga, finding rates of CO(2) uptake up to 0.3 micromol.m(-2).s(-1) in dense algal blooms. Experiments varying the irradiance resulted in light curves that resembled those of the leaves of higher plants. Red light was more effective than white and much more effective than green or blue, because of the red astaxanthin that surrounds and masks the algal chloroplasts. Integrating daily course measurements of gas exchange showed CO(2) uptake around 2,300 micromol.m(-2).day(-1) in heavily colonized patches, indicating that summer snowfields can be surprisingly productive.
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Affiliation(s)
- William E Williams
- Biology Department, St. Mary's College of Maryland, 18952 East Fisher Road, St. Mary's City, MD 20680, USA.
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29
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Zhou X. Effects of vertical inhomogeneity on snow spectral albedo and its implication for optical remote sensing of snow. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2003jd003859] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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