Exotic earthworm (Oligochaeta: Lumbricidae) assemblages on a landscape-scale in central Canadian woodlands: Importance of region and vegetation type

A growing understanding about the impacts of earthworms(Oligochaeta: Lumbricidae) on ecosystem processes and forest restorationnecessitates an examination of their role in Canadian forests where they have become invasive. Little is known about the landscape-scale responses of earthwormpopulations to different regional characteristics and vegetation typeswithin Canada’s central woodlands. We examined the regional variationof earthworm species richness, biomass, and assemblage composition across a range of four municipal regions (from south to north: Halton, Wellington, York, and Simcoe) and four habitat types (deciduous forest, mixed forest, tree plantation, and meadow) with varying soil characteristics in woodlandsof south-central Ontario, Canada. In general, earthwormcommunities differed by region but not by habitat type. The most southern regions supported the highest earthworm species richness, biomass (i.e., Lumbricusand Octolasion), and density, and this was associated with a south–north grad...