Lichenometry on Adelaide Island, Antarctic Peninsula : size-frequency studies, growth rates and snowpatches

This paper presents new lichenometric population data from the Antarctic Peninsula (67°S), and describes a new approach to lichen growth-rate calibration in locations where dated surfaces are extremely rare. We use historical aerial photography and field surveys to identify sites of former perennial...

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Bibliographic Details
Published in:Geografiska Annaler: Series A, Physical Geography
Main Authors: Golledge, Nicholas, Everest, Jeremy, Bradwell, Tom, Johnson, Joanne
Format: Article in Journal/Newspaper
Language:English
Published: Wiley-Blackwell 2010
Subjects:
Online Access:http://nora.nerc.ac.uk/id/eprint/9837/
https://nora.nerc.ac.uk/id/eprint/9837/1/Golledge_etal_2010_nora.pdf
http://www3.interscience.wiley.com/journal/118504788/home
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Summary:This paper presents new lichenometric population data from the Antarctic Peninsula (67°S), and describes a new approach to lichen growth-rate calibration in locations where dated surfaces are extremely rare. We use historical aerial photography and field surveys to identify sites of former perennial snowpatches where lichen populations now exist. As an independent check on lichen mortality by snowkill, and the timing of snow patch disappearance, we use a positive-degree day (PDD) approach based on monthly climate data from Rothera Research Station. We find that maximum growth rates for lichens <40 mm in diameter on Adelaide Island are around 0.8 mm/yr. Furthermore, we propose that our combined methodology may be more widely applicable to the Polar Regions where the construction of lichenometric dating (age-size) curves remains a problem.