Earthworm Invasions

Earthworm invasion in previously earthworm free regions (e.g., glaciated northern part of North America and Europe) has become a conservation threat to rare native species, community, and ecosystems (Gundale 2002; Hale et al. 2006; Nuzzo et al 2009; Maerz et al. 2009; Sutherland et al. 2011; Nuzzo et al. 2015). In 2011, Sunderland and coauthors identified earthworm invasions in previously earthworm free regions as one of the 15 most immerging issues of biodiversity conservation. One of the reason for the issue is that invasions by European earthworms, particularly species from Lumbricidae, have substantially altered plant population and community structure in temperate and boreal forests of northern North America (Hale et al. 2006; Frelich …show more content…
1996). Increased numbers of non-native species and their subsequent invasiveness (i.e., characterized by having adverse environmental, social, or economic effects) has endangered many native and endemic species on islands (Simberloff 1995; Steadman 1995; Sax & Gaines 2008). Recent anecdotal sightings of non-native earthworms on the previously earthworm-free San Clemente Island (SCI), in southern California (CA) are a cause for great conservation concern as the island harbors several endemic and federally endangered plants and animals. Documented widespread adverse effects of invasive earthworms in other regions of the North America suggest the possibility for similar adverse effects on SCI’s plants and animals, specifically to endemic and endangered species. Hence, there is a pressing need for a systematic scientific study to examine spatial extent and ecological impacts of introduced earthworms in the island, which may allow us first to access the potential introduction path, habitat affinities and likelihood of future spread in semi-arid Mediterranean islands; and then address the conservation concerns arise from these