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Hypolithic colonization of opaque rocks in the Arctic and Antarctic polar desert

Cockell, Charles S.; Stokes, M. Dale. 2006 Hypolithic colonization of opaque rocks in the Arctic and Antarctic polar desert. Arctic, Antarctic, and Alpine Research, 38 (3). 335-342.

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Abstract/Summary

The colonization of the underside of rocks normally requires that the material is sufficiently translucent to allow the penetration of photosynthetically active radiation. We examined the underside of 950 opaque rocks in sixteen locations in the Arctic for hypolithic colonization by photosynthetic microorganisms. Greater than 90% of rocks were colonized. The mean width of the bands of colonization was 3.1 ± 1.9 cm on Devon Island, and 3.0 ± 1.6 cm on Cornwallis Island. The width of the bands of colonization was less in the interior of frost-sorted polygons compared to their edges (in the arctic location, 0.7 ± 0.8 and 3.6 ± 1.4 cm in the interior and at the edges, respectively), suggesting the importance of frost sorting in enhancing the penetration of light around the edges of rocks to their undersides, and thus allowing colonization by photosynthetic organisms. We observed a similar pattern of colonization in antarctic polygons. The hypolithic habitat provides protection from environmental extremes. We show that within the hypolithic habitat organisms are protected from UV radiation. From radiolabeled carbon uptake measurements we estimate the productivity of the arctic communities to be approximately 0.8 g m−2 a−1, potentially as high as above-ground productivity. We discuss the potential implications of climate change for these communities.

Item Type: Publication - Article
Programmes: BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Life at the Edge - Stresses and Thresholds
ISSN: 1523-0430
Additional Information. Not used in RCUK Gateway to Research.: Full text not available from this repository
Additional Keywords: Photosythetic microorganisms, Ultraviolet
NORA Subject Terms: Biology and Microbiology
Ecology and Environment
Date made live: 22 Aug 2007 15:53
URI: http://nora.nerc.ac.uk/id/eprint/38

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