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Invasive earthworm impacts on forest soils and seedlings

Invasive Amynthas worms are invading otherwise earthworm-free soils of the northern US. This project evaluates the impacts they’ll have on forest soils and seedlings. 


Earthworms of the Asian Megascolecid genus Amynthas are invading new habitats in the previously glaciated and earthworm-free soils of the northeastern US. Furthermore, Amynthas appear to have ecosystem-specific effects, possibly due to variations in leaf litter quality. As Amynthas can live at much higher densities than European earthworm invaders and have particularly dramatic impacts on forest soils, it is critical to evaluate the ecological consequences of A. agrestis invasion across forests varying in tree species composition.

Using a combination of mesocosm and greenhouse experiments, this project addresses the following questions:

  1. Do tree species mediate the effects of Amynthas agrestis on soil carbon and nutrient cycling, soil structure, and leaf litter decomposition rates?
  2. Are Amynthas agrestis impacts on litter decomposition rates direct or indirect (i.e., alterations of the microbial community)?
  3. Do the above effects vary with Amynthas agrestis density?
  4. What are the direct and indirect (i.e., modifications of soil structure and nutrients) effects of Amynthas agrestis on tree seedling growth and survival?


This research will give us insight into the effects of these worms on plants and soils as they invade new ecosystems.

Funding sources

The Morton Arboretum

Project status