Spatial and temporal patterns in the abundance and biomass of earthworm populations in pastures in Southern Australia

Winter abundances of earthworms were monitored in five permanent pastures i n South Australia for nine years. The earthworm communities in these five p astures were dominated by exotic Lumbricidae, mostly Aporrectodea species, but indigenous Megascolecidae, e.g. Gemascolex species, were also common at some sites. Earthworm abundance and biomass varied markedly between sites, years and species, with different temporal patterns observed for some spec ies at separate sites. Dominance hierarchies varied in time within communit ies. Major changes in earthworm abundance were associated with a particular ly wet year. Aggregation indices also varied between species. Implications from the data for modelling the influence of earthworms on soil properties and pasture production and for the use of earthworms as indicators of agric ultural sustainability are discussed. The study was supplemented with data from two extensive regional surveys of earthworm communities in South Austr alia(113 sites) and western Victoria (163 sites).