abstract
Mire and hog peats at Marion Island (46� 54'S, 37� 45'E) yielded higher plate-count estimates of viable aerobic bacteria and of fungi than did soils from slope areas when expressed on a soil dry weight basis. The single fjaeldmark site investigated contained very low numbers of soil microorganisms. Manuring by seabirds and seals markedly enhanced soil N and P contents and manured sites exhibited greater populations of soil bacteria and fungi than non-manured sites. Plate-count estimates of soil microorganisms from the various island habitats were approximately similar to those reported for comparable habitats at other southern subpolar areas. The microorganisms were associated with the particulate rather than the peat solution fraction. At manured sites large numbers of microorganisms capable of reducing NO3- to NO2- and, tentatively, of bacteria forming NH3 from NO3- were found. The numbers of bacteria at these sites capable of reducing NO3- to N2 were low.
