Impact of invasive earthworm control treatments on soil microflora and vertebrate fauna in an urban northeast forest restoration site

Invasive Asian earthworms (Amynthas spp.) alter nutrient cycles, increase soil erosion, and eliminate leaf litter layers that are important habitat in forest ecosystems in the northeastern United States.   Effective earthworm management treatments are needed for successful forest regeneration.  The purpose of this study was to measure the impact of five earthworm control treatments on earthworm biomass, soil chemistry, and soil microflora.  We also assessed responses by vertebrate fauna to treatments.  A single fall application of sulfur (180 g m^-2 ) reduced total earthworm biomass for the growing season following treatment and earthworm biomass remained suppressed up to 21 months post treatment for sulfur treatments with oak litter added.  The Ca:Al ratio was 0.77 for the Sulfur and 1.01 for the Sulfur + oak treatment, necessitating regular monitoring for Al toxicity.  Total soil fungal abundance increased and the ratio of active fungal: bacterial biomass returned to within healthy levels for deciduous forest ecosystems. Sulfur and Sulfur + oak treatments had a positive effect on salamander abundance.  Pine needle amendment was the only treatment with a clear negative effect on terrestrial salamander abundance. Our results suggest that Sulfur + oak treatments may be an effective means for controlling earthworm biomass and restoring forest floor microflora conditions to favor indicator faunal species. Our results provide initial management options that both control invasive exotic earthworms while also ameliorating their negative impact on the decomposer community in northeast forest ecosystems