Earthworm invasion alters enchytraeid community composition and individual biomass in northern hardwood forests of North America
| Authors | |
|---|---|
| Year of publication | 2014 |
| Type | Article in Periodical |
| Magazine / Source | Applied Soil Ecology |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.sciencedirect.com/science/article/pii/S0929139313002370 |
| Doi | http://dx.doi.org/10.1016/j.apsoil.2013.09.005 |
| Field | Ecology |
| Keywords | earthworm invasion; Lumbricidae; Enchytraeidae; North America; soil; mesofauna |
| Description | European earthworms invade ecosystems worldwide and transform habitats by acting as ecosystem engineers. There is little knowledge of the consequences for native soil organisms. Functionally similar groups, such as enchytraeids (Annelida: Enchytraeidae), may be msot affected through changes in soil properties, but also due to competition. In 2010–2011, we studied the impact of earthworm invasion on enchytraeids at two sites in the northern hardwood forests of North America: one within the Chippewa National Forest (Minnesota) and one in the Chequamegon-Nicolet Nat. Forest (Wisconsin), USA. At each site, three plots were sampled, representing (1) a non or very slightly invaded area, (2) the leading edge of earthworm invasion and (3) a heavily invaded area with an established population of Lumbricus terrestris (among others). In total, 29 enchytraeid species were identified (some new to science, several first or second records for the continent); of those 24 occurred at the Minnesota site and 17 at the Wisconsin site. Enchytraeid assemblages differed among the three stages, although this was not equally pronounced at the two sites. Each stage was characterized by indicator species. Mean enchytraeid densities(10,700–30,400 ind./m2) did not differ significantly among the invasion stages, but were lowest at the leading edge. In the heavily invaded plot at the Minnesota site, the mean enchytraeid density and biomass in L. terrestris middens were significantly higher than in soil in-between the middens. Differences in biomass among invasion stages were most apparent for mean individual biomass of enchytraeids, being higher in the heavily invaded area than at the leading edge or in the non-invaded area (Minnesota). Compositional changes of the enchytraeid assemblage are likely to result in changes in the functioning of soil food webs. Our results suggest that earthworm invasions can cause a loss of native species in soil, including yet unknown ones, that might go unnoticed. |
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