Submitted to: Seed Production Research at Oregon State University
Publication Type: Experiment Station
Publication Acceptance Date: March 1, 2010
Publication Date: March 31, 2010
Citation: Gervais, J.A., Griffith, S.M., Davis, J.H., Cassidy, J.R., Dragila, M.I. 2010. Does Gray-Tailed Vole Activity Affect Soil Quality?. Seed Production Research at Oregon State University. 129:18-20. Interpretive Summary: Voles are well-known crop pests, especially when peak populations are present, but their role in soil fertility and impacts on agricultural sustainability are far less understood. It could be that vole activity, although destructive at times, may have underlying benefits that maybe overlooked with regards to long-term agricultural sustainability and soil health. This study examined burrow structure, soil characteristics in the immediate vicinity of vole tunnels, and measured differences in the soil chemical properties to a depth of one meter between areas of previous vole activity and areas without visible activity. We found that belowground burrowing activity by voles significantly enhanced soil nitrate levels, an important plant nutrient as well as other soil nutrients. Like the vole’s distant relatives the gophers, voles can have profound effects on soil chemistry and structure that may be related to soil quality. These changes may have a significant effect at landscape scale and possibility not considered when viewing long-term agricultural sustainability.
Technical Abstract: Voles are well-known crop pests, especially when peak populations are present, but their role in soil fertility and impacts on agricultural sustainability are not well understood. Five months after the abrupt disappearance of a peak in a gray-tailed vole (Microtus canicaudus) population, we examined burrow structure, determined concentrations of trace elements, carbon and nitrogen in the soil immediately surrounding vole burrows, and compared soil chemical properties to a depth of 90 cm between areas with prior vole activity and areas of no activity. Vole tunneling activity was confined to the top 10 cm of the soil profile and was coincident with the majority of root biomass. Soil NH4+, NO3-, extractable organic carbon, and soil organic matter were greater below vole tunnels than above; however, due to small sample sizes, differences were not significant. There were no differences in trace elements with respect to position around vole tunnels. Vole activity was associated with increased soil nitrate concentrations and decreased soil pH to a depth of 90 cm, indicating that nitrification might be enhanced by vole activity, and that this effect continues after vole populations crash. Greater inorganic nitrogen could have long-term effects on ecosystem productivity. The effects voles have on soil processes that influence carbon and nutrient cycle requires further investigation.