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  • Soil temperature measurements taken at various sites on Signy Island during the 2008-2009 field season. These measurements were used as part of an investigation to understand the effect of temperature and moisture on the availability of different nitrogen forms.

  • To investigate the availability of peptides in the soils on Signy Island, soil solutions were sampled throughout the summer season, from mid November 2008 until early March 2009. Soil solution samples were extracted under vacuum, with minimal disturbance to the soil, through small porous tubes. A total of 19 sites across the island were sampled in areas dominated by all the major primary producers, vascular plants, mosses, algae and lichens. The collected soil solution samples were analysed for different forms of nitrogen, including peptides.

  • Field measurements were used to determine the availability of peptide nitrogen to photosynthetic organisms and soil microbes. In order to fully understand their significance in the Maritime Antarctic nitrogen cycle it was also necessary to examine the ability of organisms to utilise the available peptides. For this reason, isotopically-labelled (15N and 13C) nitrogen compounds, including various peptides, were used to determine their rate of uptake by soil microorganisms and plants. These experiments were carried out on Signy to minimise any changes to organisms during transit.