Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable (<0.45 μm) iron (6-81 kg km a) than icebergs (0.0-1.2 kg km a). Glacier-fed streams also export more acid-soluble iron (27.0-18,500 kg km a) associated with suspended sediment than icebergs (0-241 kg km a). Significant fluxes of filterable and sediment-derived iron (1-10 Gg a and 100-1,000 Gg a, respectively) are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change.
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http://dx.doi.org/10.1038/ncomms14499 | DOI Listing |
Fungal Biol
December 2024
British Antarctic Survey, NERC, Madingley Road, Cambridge, CB3 0ET, United Kingdom; Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, EH3 5LR, United Kingdom.
The occurrence of mycothalli, symbioses between liverworts and fungi, is poorly documented in sub-Antarctica, and biogeographical patterns in Serendipita, the main fungal genus forming the symbiosis, remain understudied. Here, 83 specimens of 16 leafy liverwort species were sampled from sub-Antarctic South Georgia and were examined for mycothalli. Microscopy was used to enumerate fungal structures in liverwort tissues, and sequencing of fungal ribosomal DNA was used to determine the taxonomic and biogeographical affinities of the fungi.
View Article and Find Full Text PDFAn Acad Bras Cienc
November 2024
Universidade Federal de Viçosa (UFV), Núcleo Terrantar, Departamento de Solos, Vila Gianetti, 8, 36570-075 Viçosa, MG, Brazil.
Sci Rep
November 2024
Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, UK.
Parasit Vectors
November 2024
Division of Life Sciences, Korea Polar Research Institute, Incheon, Republic of Korea.
Sci Total Environ
December 2024
Grupo de Microbiología Integrativa, Departamento de Biología, Facultad de Ciencias, Universidad de Chile, Santiago, Chile. Electronic address:
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