Effects Of Invasive Pheretimoid Jumping Worms On The Growth And Mycorrhizal Associations Of Winter Rye

Invasive Asian jumping worms (family Megascolecidae) are rapidly spreading across North America, however, their impacts on plant-fungal symbioses are poorly understood. In this study, we used a 2x2 factorial design to investigate the individual and combined effects of jumping worms and their castings on soil chemistry, winter rye (Secale cereale) growth, and infection by arbuscular mycorrhizal fungi (AMF). We established 120 five-gallon pots arranged into 30 replicate blocks and applied four treatments: a control, worms only, castings only, and worms + castings. Our data showed that castings significantly increased nitrate, ammonium, and soil organic matter, while reducing phosphorus, potassium, and magnesium. Although no difference in winter rye biomass was observed across treatments, there was a slight decrease in seedling survival in response to castings. Notably, arbuscule abundance increased in the presence of worms, while hyphal colonization decreased in response to both worms and castings. We suggest that this could be a compensatory infection response by AMF, in which the increased exchange offsets diminished hyphal networks. These findings contribute to a growing understanding of the complex interactions between soil, plants, and microbes amidst jumping worm invasion and have implications for management strategies.