|University of Akron
|Ecology; Forestry; Biology; exotic earthworms; white-tailed deer; understory; plant communities; biotic homogenization; FQAI; Amynthas; Lumbricus
|Full text PDF:
Temperate forests of North America are being altered by the combined effects of two ecosystem engineers: white-tailed deer, Odocoileus virginianus, and exotic earthworm species from Europe and Asia. The intense pressure of herbivory from white-tailed deer alters the structure, abundance and diversity of plants in the forest understory. Exotic earthworm invasion can dramatically change the physical and chemical attributes of forest soils, altering plant-soil interactions which can facilitate changes in understory plant communities. Here we have used a deer exclosure study to isolate the impacts of white-tailed deer from those of exotic earthworms in order to better understand how they interact in shaping temperate forest plant communities. Results confirm that deer can dramatically reduce the abundance, richness and diversity of native plants. Contrary to past studies we found no evidence that exotic earthworms themselves reduce native plant abundance or diversity. Exotic earthworms are shown to alter the plant community through the loss of specialist species which are replaced by generalist and exotic species. This is the first in situ study of exotic earthworms in temperate forests to account for deer impacts and identify the unique and aspects of exotic earthworm on forest plant communities. The combined effects of these engineering species can dramatically alter the forest plant community and pose a formidable threat to the conservation of biodiversity.