Community structure of aquatic invertebrates associated with Elodea canadensis in its native and invasive range

Abstract

Invasive species are a global concern impacting biodiversity, community structure, and ecological function of entire ecosystems. Elodea canadensis (Canadian waterweed) is a submerged aquatic macrophyte native to southern Canada and the 48 contiguous United States but invasive in Alaska. The purpose of our study was to compare aquatic macroinvertebrate communities associated with E. canadensis in native (Illinois) and invasive (Alaska) areas. Functional feeding group community structure of E. canadensis-associated macroinvertebrates was different in the invasive and native range. Collector-filterer relative abundance was higher in the invasive range, whereas predator-engulfer relative abundance was higher in the native range. Furthermore, shredder-herbivore density in E. canadensis beds was higher in the native range than in the invasive range. Our results suggest that the successful establishment of E. canadensis in Alaska is likely facilitated by reduced herbivory and that the continued spread of E. canadensis will alter ecosystem structure and function of the Copper River Delta, Alaska, and the ecosystem services it provides.