Do Invasive Earthworms Impact Water Quality?

Ben Vermilyea attended the Natural Resource Conservation Academy (NRCA) at UCONN this past summer 2015.  He approached White Memorial seeking a community partner so that he could apply what he learned at the NRCA.  I have been interested to explore if exotic earthworms could increase soil erosion near headwater streams thereby impacting water quality when they incorporate the mineral layers and consuming leaf litter on the surface.  We've observed leaf litter loss in some areas on the property so severe that by the end of the summer the soils are nearly completely denuded of leaf litter before the next leaf litter crop.  This exposes the soil the air and encourages soil erosion either by the falling water droplets hitting the soil or by sheeting.  Ben and I developed a novel method for measuring soil erosion.  We installed fabric hammocks along the stream bank that collected soil particles before they entered a stream that flowed near an earthworm invaded area and compared that data with another stream that was not impacted by earthworms.  We observed some important patterns.  The earthworms indeed changed the soil properties.  Although we did not observe significant differences between the weights of the soil particles entering both streams, we performed a power analysis which suggested a significant difference could be detected if we increased our sample size to a total of 451 hammocks samples.  We feel this it is feasible to acheive this in future research, so stay tuned.  Obviously, this is based on certain assumptions but we may not need to as many samples if we were to compare headwater streams that flow through regions that are more severely impacted by exotic earthworms.

Ben will present the poster (above) at the Connecticut Conference on Natural Resources on March 14, 2016 at UCONN.

Congratulations Ben!

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