Spatial dynamics of an invasive earthworm (Amynthas sp.) in West Liberty University’s campus woods community.

Abstract

Asian pheretimoid earthworms (Amynthas sp.) have been reported in the hardwood forests of the eastern United States with increasing frequency. These invasions can have highly negative ecosystem-wide impacts. Amynthas sp. are prolific breeders capable of reaching high densities in forest soils. They consume large quantities of leaf litter, disturbing natural soil horizons, draining available nutrients and damaging plant communities. In the summer and fall of 2021, population surveys were conducted in an area of West Liberty University’s campus woods community known to be infested with pheretimoid worms. Spatial dynamics were examined using SADIE analysis. It was found that Amynthas sp. showed a trend towards aggregation in both the summer and fall, with a more evident trend towards aggregation in the fall. An analysis of spatial association showed that the distributions between consecutive samples were positively associated. This indicates stability of aggregations over short timescales in both summer and fall. Understanding the population dynamics of Amynthas sp. and their interactions with native communities will aid in the development of management strategies to prevent the spread of this invasive and reduce the disturbance of native forest ecosystems.