Impacts of Invasive Earthworms (Delayed from 3/15 due to weather)


Tuesday, April 4, 2017 - 7:00pm to Wednesday, April 5, 2017 - 6:45pm




Unitarian Church Annex, Buffalo St. Ithaca - second story


Annise Dobson, Department of Natural Resources, Cornell


Following the previous last glacial maximum approximately 22,000 yrs ago, northeastern North American forests developed in the absence of earthworms. Many settlers imported European plants that likely had earthworms or earthworm cocoons (egg cases) in their soils. More recently, the widespread use of earthworms as fishing bait has spread them to more remote areas of the continent. Without earthworms, fallen leaves are slowly decomposed by microbes, fungi and soil invertebrates. This creates a spongy layer of organic duff, which is the natural substrate for native woodland wildflowers and many tree seedlings. Invading earthworms consume the leaves that create the duff layer and are capable of eliminating it completely. In this talk, Annise will discuss the consequences of earthworm invasion and subsequent loss of the organic horizon for understory plant communities