DISTRIBUTION, PREVALENCE AND INTENSITY OF EARTHWORM POPULATIONS IN ARABLE LAND AND GRASSLAND IN SCOTLAND

The earthworms of arable and pasture fields from 100 randomly chosen a rable farms were identified and counted and their relationship with so il factors examined. Thirteen species of earthworm were recorded inclu ding Lumbricus friendi from Scotland for the first time. The most prev alent and numerous species were Aporrectodea longa, Aporrectodea calig inosa and Lumbricus terrestris. All earthworm species had cosmopolitan distributions apart from Aporrectodea nocturna and Lumbricus festivus which were confined to southern/central Scotland. Four soil character istics (% moisture, % sand, % organic matter and pH) shared no relatio nship with species recorded but tillage may have had a detrimental eff ect on species composition and size of population. It is suggested tha t the magnitudes of the earthworm populations found, particularly in p ermanent pasture, were important in maintaining soil structure and fer tility, and the spread of the New Zealand flatworm (Artioposthia trian gulata), an obligate predator of earthworms, could have a considerable impact on agricultural productivity and wildlife in Scotland.