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Prescribed Fire to Stem the Tide of Earthworm Invasion

Photo of Asian earthworm (Amynthas agrestis).  This species is invading eastern deciduous forests across North America. USDAForest ServiceAsian earthworm (Amynthas agrestis). This species is invading eastern deciduous forests across North America. USDAForest ServiceSnapshot : Asian earthworms are currently invading eastern deciduous forests from Georgia to Vermont. Because these earthworms eat leaf litter in the forest floor, Forest Service scientists and collaborators hypothesized that applying some heat and removing some of this food source with prescribed fire might slow or repel these invaders. In a controlled experiment, the scientists found that fire resulted in much lower reproductive success for the invasive earthworms. This may have application in controlling invasions in the field.

Principal Investigators(s) :
Callaham, Mac 
Research Location : Chattahoochee-Oconee National Forest; Great Smoky Mountains National Park; Whitehall Forest, University of Georgia.
Research Station : Southern Research Station (SRS)
Year : 2015
Highlight ID : 906

Summary

Biological invasions are one of the most significant global-scale problems caused by human activities. Introduced Asian earthworms are currently invading eastern deciduous forests in North America, including some relatively undisturbed forests. Because fresh leaf litter is presumably a major food source for these forest floor dwelling species, Forest Service scientists examined whether prescribed fire could be used to reduce food supply and potentially control reproduction and spread of invasive earthworms. The scientists constructed eight experimental beds with 100 earthworms each, and burned half of them with low intensity fires. The fires resulted in minimal heating of mineral soil but litter mass was significantly reduced. No reductions in the number of adult earthworms were detected, but the hatching rates of cocoons were significantly lower in burned beds. The study shows that prescribed fire causes reduced reproduction rates and decreased food availability for the next generation of earthworms, and this may have significant application in the management of earthworm invasions in southern deciduous forests.

Forest Service Partners

External Partners

  • Chattahoochee-Oconee National Forest
  • Dr. Hiroshi Ikeda, Hirosaki University, Japan

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