Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard

Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria a...

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Published in:Biogeosciences
Main Authors: Vonnahme, T. R., Devetter, M., Žárský, J. D., Šabacká, M., Elster, J.
Format: Text
Language:English
Published: 2018
Subjects:
Online Access:https://doi.org/10.5194/bg-13-659-2016
https://www.biogeosciences.net/13/659/2016/
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spelling ftcopernicus:oai:publications.copernicus.org:bg30667 2023-05-15T15:12:19+02:00 Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard Vonnahme, T. R. Devetter, M. Žárský, J. D. Šabacká, M. Elster, J. 2018-09-27 application/pdf https://doi.org/10.5194/bg-13-659-2016 https://www.biogeosciences.net/13/659/2016/ eng eng doi:10.5194/bg-13-659-2016 https://www.biogeosciences.net/13/659/2016/ eISSN: 1726-4189 Text 2018 ftcopernicus https://doi.org/10.5194/bg-13-659-2016 2019-12-24T09:52:47Z Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae) and relations to their potential grazers, such as tardigrades and rotifers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances but rather a positive correlation with eukaryotic microalgae. Shared environmental preferences and a positive effect of grazing are the proposed mechanisms to explain these correlations. Most microalgae found in this study form colonies (< 10 cells, or > 25 µm), which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in redundancy (RDA) and principal component (PCA) analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of nutrient input by bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting nutrients are the main factor driving variation in the community structure of microalgae and grazers. Text Arctic glacier Svalbard Copernicus Publications: E-Journals Arctic Guano ENVELOPE(141.604,141.604,-66.775,-66.775) Svalbard Biogeosciences 13 3 659 674
institution Open Polar
collection Copernicus Publications: E-Journals
op_collection_id ftcopernicus
language English
description Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae) and relations to their potential grazers, such as tardigrades and rotifers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances but rather a positive correlation with eukaryotic microalgae. Shared environmental preferences and a positive effect of grazing are the proposed mechanisms to explain these correlations. Most microalgae found in this study form colonies (< 10 cells, or > 25 µm), which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in redundancy (RDA) and principal component (PCA) analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of nutrient input by bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting nutrients are the main factor driving variation in the community structure of microalgae and grazers.
format Text
author Vonnahme, T. R.
Devetter, M.
Žárský, J. D.
Šabacká, M.
Elster, J.
spellingShingle Vonnahme, T. R.
Devetter, M.
Žárský, J. D.
Šabacká, M.
Elster, J.
Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
author_facet Vonnahme, T. R.
Devetter, M.
Žárský, J. D.
Šabacká, M.
Elster, J.
author_sort Vonnahme, T. R.
title Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
title_short Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
title_full Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
title_fullStr Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
title_full_unstemmed Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard
title_sort controls on microalgal community structures in cryoconite holes upon high-arctic glaciers, svalbard
publishDate 2018
url https://doi.org/10.5194/bg-13-659-2016
https://www.biogeosciences.net/13/659/2016/
long_lat ENVELOPE(141.604,141.604,-66.775,-66.775)
geographic Arctic
Guano
Svalbard
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Guano
Svalbard
genre Arctic
glacier
Svalbard
genre_facet Arctic
glacier
Svalbard
op_source eISSN: 1726-4189
op_relation doi:10.5194/bg-13-659-2016
https://www.biogeosciences.net/13/659/2016/
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container_title Biogeosciences
container_volume 13
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