Alpine river microbial community response to shrinking glaciers

Arctic and alpine zones will warm more and faster than all other parts of Earth to 2050 and beyond, causing widespread changes in snow and ice cover. Changes will occur much more rapidly than other ecosystems due to the extremely high climatic sensitivity of glacier/snow pack mass balance and meltwater generation into rivers. This PhD will quantify the implications of glacier shrinkage and retreat for river microbial communities. Microbial communities regulate the major global biogeochemical cycles and support entire food webs/ecosystems, but respond rapidly to environmental change. Yet most previous studies of biodiversity response to glacier retreat have focused principally on invertebrate larvae. We can predict that it will be possible to generalise patterns of insect biodiversity loss with glacier shrinkage to microbial communities, although microbial richness might be higher due to diverse inputs (soil, ice, wind-blown, tributary) to rivers, even in heavily glacierized mountains that otherwise have low macrofaunal diversity. We might also expect to see high turnover between putatively active and dormant taxa 11, so biofilm activity should also respond to glacier shrinkage.

For further information, please see http://www.nercdtp.leeds.ac.uk/projects/index.php?id=531 or contact Dr Lee Brown ([Email Address Removed])

This PhD project will use river ecosystems as model systems because they have disproportionately high biodiversity compared to their coverage of Earth’s surface, they are especially sensitive to climate change particularly in cold zones, and are major players in global elemental cycles. The PhD will use field-surveys with space-for-time substitution of catchment glacier cover to represent different stages of glacier retreat. A series of samples have already been collected and preserved from rivers of the Austrian Alps, French Pyrenees, Alaskan Coastal Range, Nepalese Himalayas and New Zealand Alps. The project will provide opportunities for the student to augment these samples with collections of their own from at least one other biogeographic locations (potentially Scandinavia, Greenland and/or Iceland). The central aim of the work will be to determine the composition and activity of microbial biofilms. There will also be opportunities to design and implement experiments to quantify the functional roles (e.g. primary production, respiration, nutrient uptake) of river biofilms.