Glaciers and ice sheets constitute biomes in their own right, hosting diverse assemblages of micro-organisms including viruses, bacteria, fungi, micro-algae and micro-fauna. Such communities are known to play important roles in globally significant processes, e.g. organic matter production and transformation. Positive feedback mechanisms are also apparent between biological communities and melting of the cryosphere they inhabit, with potentially significant implications for the long-term integrity of these systems. For example, blooms of pigmented bacteria and micro-algae cause localized albedo-reduction and consequent increases in surface melt in supraglacial habitats, facilitating continued bloom development. To allow projection of the fate and impacts of biological communities in glacial and ice sheet environments, it is fundamental to constrain the factors that drive and control these communities in-situ.

This session includes studies on i) the regulation of biological communities by abiotic stressors (e.g. nutrient limitation, freeze-thaw cycles, desiccation, excessive UV- and photosynthetically active –radiation), ii) the role of biotic interactions between functional groups in sustaining and/or limiting life, and iii) psychrophilic adaptations permitting persistence in the cryosphere. We invite contributions from research spanning all disciplines e.g. ecophysiological, biogeochemical, genomic and modelling approaches.