Project Title: Earthworms: A Real Threat to Our Northeastern Sugarbushes Investigators: Fig. 1. Adult Amynthas worm found in leaf litter on the forest floor. They could be anywhere, and they are spreading everywhere.
Bruce L. Parker1, Donald R. Tobi1 and Josef Gorres2 1. The University of Vermont Entomology Research Laboratory 661 Spear Street, Burlington, VT 05405�0105 bparker@uvm.edu, dtobi@uvm.edu Tel: 802:656-5440
2. The University of Vermont Plant and Soil Science Department 258 Jeffords Hall, Burlington, VT 05405 jgorres@uvm.edu
Project Summary/Abstract: Historically earthworms have been perceived as indigenous native organisms that enhance soil fertility. Few realize they are exotic species, some of which are invasive and represent a serious threat to sugarbush health. These worms are disrupting the natural biodiversity by transforming the forest floor structure and chemistry. New particularly aggressive, more destructive East Asian earthworm species (genus Amynthas, a.k.a. Alabama Jumpers or Snake Worms) are colonizing our Northern forests (Fig. 1). In the past these worms were mainly observed in warmer Southern climates, where they are used as bait and compost worms. They have now spread to Vermont and other New England states. In areas where Amynthas has become established, the understory litter had disappeared and there was no sign of canopy tree species regeneration. A Shelburne VT sugar maple stand with a complete lack of understory plants was found to be infested with Amynthas worms in 201011 (Fig. 2). Little is known about the distribution of Amynthas worms, or their impact on sugar maple regeneration in Vermont and other northern states. We were recently notified that a proposal we submitted to the North American Maple Syrup Council (November 2014), also dealing with the abundance and distribution of exotic worms, was selected for funding. That project compliments work we propose herein. With funding from the Chittenden County Maple Sugarmakers we will be able to expand the scope of this research to better determine the current abundance and distribution of worm species in Northern sugarbushes relative to forest management practices, and assess their impact on understory diversity, maple regeneration and various soil characteristics. Project Objectives: Long term goal: Gain understanding of the distribution, abundance, species diversity and impact of invasive exotic earthworms in sugarbushes in northern New England, from which strategies to combat them can be considered. Supporting objectives: 1. Determine the distribution, abundance and species diversity of invasive exotic earthworms
in sugarbushes in northern New England relative to forest overstory and understory composition in working sugarbushes across three coldhariness zones. 1