Changes in soil nematode populations indicate an annual life cycle at Cape Hallett, Antarctica

Soil biological studies have suggested that generations of terrestrial nematodes in continental Antarctica may take many years. We sampled soil nematodes at three sites in the Adélie penguin colony at Cape Hallett on four dates in a two month sampling period (16 November 2002–18 January 2003). The size class distribution of over 3500 nematodes, and the occurrence of adults, indicate an annual life cycle of the bacterial-feeding Panagrolaimus davidi and Plectus murrayi, at each site. Nematode abundance ranged from 2 to 1375/g dry soil. Moderate temperatures and the regular presence of free water underlie this biological activity and related contribution to soil processes.