Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied. The major purpose of our study is the presentation and description of morphological diversity, chemical and photoautotrophs composition, and organic matter content of cryoconite sampled from 33 polar and mountain glaciers around the globe. Observations revealed that cryoconite is represented by various morphologies including loose and granular forms. Granular cryoconite includes smooth, rounded, or irregularly shaped forms; with some having their surfaces covered by cyanobacteria filaments. The occurrence of granules increased with the organic matter content in cryoconite. Moreover, a major driver of cryoconite colouring was the concentration of organic matter and its interplay with minerals. The structure of cyanobacteria and algae communities in cryoconite differs between glaciers, but representatives of cyanobacteria families Pseudanabaenaceae and Phormidiaceae, and algae families Mesotaeniaceae and Ulotrichaceae were the most common. The most of detected cyanobacterial taxa are known to produce polymeric substances (EPS) that may cement granules. Organic matter content in cryoconite varied between glaciers, ranging from 1% to 38%. The geochemistry of all the investigated samples reflected local sediment sources, except of highly concentrated Pb and Hg in cryoconite collected from European glaciers near industrialized regions, corroborating cryoconite as element-specific collector and potential environmental indicator of anthropogenic activity. Our work supports a notion that cryoconite may be more than just simple sediment and instead exhibits complex structure with relevance for biodiversity and the functioning of glacial ecosystems.

Department of Analytical Chemistry Faculty of Chemistry Adam Mickiewicz University Poznań Poland

Department of Animal Taxonomy and Ecology Faculty of Biology Adam Mickiewicz University Poznań Poland

Department of Animal Taxonomy and Ecology Faculty of Biology Adam Mickiewicz University Poznań Poland; Geohazards Research Unit Institute of Geology Adam Mickiewicz University Poznan Poland

Department of Avian Biology and Ecology Faculty of Biology Adam Mickiewicz University Poznań Poland

Department of Botany and Plant Ecology Wrocław University of Environmental and Life Science pl Grunwaldzki 24a 50 363 Wrocław Poland

Department of Earth and Environmental Sciences University of Milano Bicocca Milan Italy

Department of Earth Sciences Ardito Desio University of Milan Milan Italy

Department of Earth Sciences Graduate School of Science Chiba University Chiba Japan

Department of Ecology Faculty of Science Charles University Prague Czech Republic

Department of Entomology and Nematology University of Florida Gainesville FL USA

Department of Environmental Microbiology and Biotechnology Faculty of Biology University of Warsaw Warsaw Poland

Department of Environmental Science and Policy University of Milan Milan Italy

Department of Environmental Science and Policy University of Milan Milan Italy; Laboratoire d'Ecologie Alpine University Grenoble Alpes Univ Savoie Mont Blanc CNRS LECA Grenoble France

Department of Environmental Sciences Aarhus University Aarhus Denmark

Department of Environmental Sciences Western Norway University of Applied Sciences Sogndal Norway

Department of Hydrobiology Faculty of Biology Adam Mickiewicz University Poznań Poland

Department of Mass Spectrometry Institute of Nuclear Physics Polish Academy of Sciences Kraków Poland

Department of Water Protection Faculty of Biology Adam Mickiewicz University 61 614 Poznań Poland

Ecology and Evolutionary Biology Department University of Colorado Boulder CO USA

Field Research Center for Northern Biosphere Hokkaido University Sapporo Japan

Geohazards Research Unit Institute of Geology Adam Mickiewicz University Poznan Poland

Graduate School of Science and Engineering Chiba University Chiba Japan

Institute of Hydrology Meteorology and Environmental Studies IDEAM Bogota Colombia

Institute of Polar Sciences National Research Council Venice Italy

Private person Poznań Poland

State Institution National Antarctic Center of Ministry of Education and Science of Ukraine Kyiv Ukraine; Institute of Molecular Biology and Genetics National Academy of Sciences of Ukraine Kyiv Ukraine

University of Silesia in Katowice Institute of Earth Sciences Bedzinska 60 41 200 Sosnowiec Poland

Citace poskytuje Crossref.org

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