Experiments to determine the processes governing the colonization of micro-organisms in extreme Antarctic fellfields

In Antarctica, moisture, temperature and other climatic regimes and the quality and stability of the prevailing mineral substrate act as extreme limiting factors for colonization by microbes, cryptograms and invertebrates. Ice free areas of coarse or fine mineral debris are known as fellfields. The microclimatic and edaphic features of fellfields and the processes governing their colonization community development, and the survival strategies of their biota was the aim of the British Antarctic Surveys program, Fellfield Ecology Research Program (FERP). FERP was focussed at Signy Island and South Orkney Island and studies in the Ross Sea, especially the Dry Valleys, will provide comparisons with the more maritime environment of Signy and South Orkney Islands. Fellfield sites in South Victoria Land, including the Blue Glacier regions, East and West Beacon, Lake Vanda, Shapeless Mountain and the Balham and Barwick Valley's and Ross Island (Cape Bird, Cape Royds and Cape Evans) were visited for examination and sampling at diverse fellfield sites. Concurrent aerial samples were also taken. Examples of soil crusts, epilithic, chasmolithic and endolithic microbial communities were collected to determine common factors between colonization processes. Isolates of bacteria , yeasts, fungi and algae were obtained from aerial and terrestrial samples. Physical perturbation and amendments of fine mineral debris and rock flakes was investigated at two sites at Keble Valley, Cape Bird (one dry and one wet). Soil crust formation and rock colonization was monitored by epifluorescence microscopy. The influence of temperature, moisture, nutrient availability and substrate structure was included. Extant soil crusts and epilithic communities were also examined. Aerial microbial and cryptogamic propagules were collected using Rotorod samplers and the resulting collector strips were examined.