Effects of English ivy (Hedera helix) on seed bank formation and germination

English ivy Hedera helix L. is rapidly invading forest ecosystems in the southeastern United States, leading to a decrease in the diversity of native plant species. To determine the underlying mechanism for the loss of diversity and understand the potential for restoration of impacted habitats, we examined whether ivy had a negative effect on seed bank formation and germination. We sampled the seed bank and the summer and fall seed rains in areas with and without ivy. In addition, we determined potential allelopathic effects of ivy on germination of Coreopsis lancelota seeds. The density and species diversity of the seed bank and seed rains were not significantly different between areas with and without ivy. However, ivy led to a marginally significant reduction in the germination rate of C. lancelota seeds. Yet, the effect of ivy on germination only occurred when ivy plants were present. Germination rates did not differ in soil from areas with and without ivy. Our results suggest that native plant communities can regenerate naturally from the seed bank if English ivy were removed.