The distribution and effect of non-native earthworms on soil structure in northern Michigan

Abstract

Understanding the change in abundance of exotic earthworms and their effect on soil structure is crucial in assessing their influence on different microhabitats. Studies comparing the effect of earthworm species on environments in northern Michigan remain limited. To address this, we conducted experiments in plots of different soil compositions to survey the abundance and distribution of earthworms. Four earthworm species have been found in present-day microhabitats of northern Michigan: Lumbricus rubellus, Lumbricus terrestris, Dendrobaena octaedra and Aporrectodea spp. We found that there were significantly more earthworms in nutrient rich soils than in sandy soil environments. In addition, a thick O-A horizon mixture correlated with greater earthworm abundance. This study will allow for greater understanding of the influence and abundance of non-native earthworms in different microhabitats.