Species composition and seasonal variation of earthworms and their effect on soil properties in southern Ontario, Canada

Abstract

Four never cultivated, well drained forest sites representing the range of soil textures in the Lake Erie Basin of southern Ontario (approx. 42°N, 80°W) were characterized monthly during the growing season as to their earthworm populations, using the formalin extraction technique. Earthworm densities and biomasses ranged from 5 to 114 m −2, and 0.5 to 11 g dry wt m −2 respectively. There were a total of six lumbricid species at the four sites, but the anecic species, Lumbricus terrestris (L.) was the dominant contributor to faunal biomass at three of the sites. Earthworms at the fourth site were two small endogeous species that had the lowest abundance and biomass for earthworms of the four sites. The influence of faunal activity on soil properties was measured by the 137Cs (originating as fallout from atmospheric nuclear tests) distribution within 1 cm thick layers to a depth of 15 cm. Organic matter and 137Cs distribution with depth were functions of both earthworm abundance and species. Sites with anecic earthworms had 137Cs distributed throughout the surface horizons, whereas the site with endogeous species had higher 137Cs levels remaining at or near the soil surface.