Loss Lab
Global Change Ecology & Management
Scott R. Loss
Associate Professor
Dept. of Natural Resource Ecology & Management
Oklahoma State University
Invasive Earthworms
Non-native earthworms from Europe and Asia have invaded much of North America, with devastating consequences to ecosystems. Impacts of these invasions have been particularly severe in areas that were historically earthworm-free, such as previously glaciated northern forests and oceanic islands, where effects include changes in nutrients, soil structure, chemistry, and biology, and the litter layer. These impacts cascade up to plants and animals. We have led several studies of invasive earthworm effects on birds, plants, and soil mycorrhizal fungi in forests and grasslands.
Scott's PhD research in hardwood forests of Minnesota and Wisconsin illustrated that invasive earthworms also impact ground-dwelling birds. Specifically, earthworm-caused changes to vegetation and the litter layer reduce density and nest survival of bird species that nest on the ground (e.g. the Ovenbird and Hermit Thrush).
We have also developed an invasive earthworm rapid assessment tool that classifies hardwood forests into 5 stages of invasion severity based on visual assessment of the soil, leaf litter, and vegetation. This method has been used to quantify earthworm invasions and focus management across many forests in the northern U.S.
Historically earthworm-free hardwood forest without (above) & with (below) non-native earthworms
Current and Recent Invasive Earthworm Research in the Loss Lab
Led by master's student Lucas Bobay (below left), and in collaboration with Dr. Sam Fuhlendorf's lab at OSU and Dr. Torre Hovick's lab at North Dakota State University, we are studying effects of fire and grazing on native and non-native earthworm populations in tallgrass prairies of the Flint Hills region, specifically, at the Joseph H. Williams Tallgrass Prairie Preserve in Oklahoma. Lucas is also investigating whether earthworms provide a food source for migratory shorebirds that stopover in recently burned areas in the region, like the American Golden Plover (pictured eating an earthworm in a recently burned patch at the Tallgrass Prairie Preserve).
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Led by master's student Yevgeniya Malyutina (far right, with OSU chapter of The Wildlife Society helping her collect earthworms), we are conducting a study of effects of non-native earthworms on plant communities in Great Plains grasslands. In collaboration with Dr. Gail Wilson's lab, this work includes both a field and greenhouse study (right, earthworm in greenhouse mesocosm) evaluating if any earthworm impacts on plants arise from effects on arbuscular mycorrhizal fungi (root symbionts many grassland plants require to thrive).
Led by postdoc Shishir Paudel (on left in leftmost photo), we studied impacts of non-native earthworms on the historically earthworm-free San Clemente Island (SCI), California (middle). Through this work, we published a study documenting the spatial distribution of earthworms on SCI (right) and also found that non-native earthworms on the island may facilitate invasions of non-native plants.
Shishir also led publication of a major review in Ecology synthesizing evidence that non-native earthworm effects on arbuscular mycorrhizal fungi are likely at the root of many of the changes in plant communities brought about by earthworm invasions (conceptual diagram from paper below).
Scott also published a study of the local-scale correlates of both non-native and native North American earthworms in Great Plains grasslands. This work, published in Biological Invasions, was based on data collected entirely by OSU undergraduate students (below) in Scott's Applied Field Ecology class.
In addition to research led by the Loss Lab, we have contributed data and expertise as co-authors of major international reviews including a paper in Science (right) identifying global patterns of earthworm diversity; a review of ecosystem cascades caused by invasions in Frontiers in Ecology and the Environment (bottom), and a meta-analysis of invasion effects on forest plants in Global Change Biology.
All Invasive Earthworm Publications (Loss Lab members in bold)
Malyutina, Y., Wilson, G.W.T., Duell, E.B., Loss, S.R. 2023. Evaluating effects of native and non-native earthworms on arbuscular mycorrhyzal fungi and plant communities in a North American tallgrass prairie. Biological Invasions 25:455-470.
Phillips, H.R.P., …. Loss, S.R., Paudel, S., … Eiesenhauer, N. (>140 authors). 2021. Global data on earthworm abundance, biomass, diversity and corresponding soil properties. Scientific Data 8:136.
Phillips, H.R.P., …. Loss, S.R., Paudel, S., … Eiesenhauer, N. (>140 authors). 2019. Global distribution of earthworm diversity. Science 366:480-485.
Frelich, L.E., Blossey, B., Cameron, E.K., Davalos, A., Eisenhauer, N., Fahey, T., Groffman, P., Larson, E., Loss, S.R., Maerz, J., Nuzzo, V., Yoo, K, Reich, P.B. 2019. Side-swiped: Ecological cascades emanating from earthworm invasion. Frontiers in Ecology and the Environment 17:502-510.
Paudel, S, Benavides, J.C., MacDonald, B., Longcore, T., Wilson, G.W.T., Loss, S.R. 2017. Determinants of native and non-native plant community structure on an oceanic island. Ecosphere 9:e01927.
Loss, S.R., Paudel, S., Laughlin, C.M., Zou, C. 2017. Local-scale correlates of native and non-native earthworm distributions in a grassland encroached by a native juniper. Biological Invasions 19:1621-1635.
Craven, D., Thakur, M.P., Cameron, E.K., Frelich, L.E., Beausejour, R., Blair, R.B., Blossey, B., Burtis, J., Choi, A., Davalos, A., Fahey, T.J., Fisichelli, N., Gibson, K., Handa, I.T., Hopfenspberger, K., Loss, S.R., Nuzzo, V., Maerz, J., Sackett, T., Scharenboch, B., Smith, S.M., Vellend, M., Umek, L.G., Eisenhauer, N. 2017. The unseen invaders: introduced earthworms as drivers of change in plant communities in North American forests (a meta-analysis). Global Change Biology 23:1065-1074.
Paudel, S., MacDonald, B., Longcore, T., Wilson, G.W.T., Loss, S.R. 2016. Predicting spatial extent of invasive earthworms on an oceanic island. Diversity and Distributions 22:1013-1023.
Paudel, S., Longcore, T., MacDonald, B., McCormick, M.K., Szlavecz, K.,Wilson, G.W.T., Loss, S.R. 2016. Belowground interactions with aboveground consequences: Invasive earthworms and arbuscular mycorrhizal fungi. Ecology 97:605-614.
Loss, S.R., Blair, R.B. 2014. Earthworm invasions and the decline of clubmosses (Lycopodium spp.) that enhance nest survival rates of a ground-nesting songbird. Forest Ecology and Management 324:64-71.
Loss, S.R., Hueffmeier, R.M., Hale, C.M., Host, G.E., Sjerven, J., Frelich, L.E. 2013. Earthworm invasions in northern hardwoods forests: a rapid assessment method. Natural Areas Journal 33:21-30.
Loss, S.R. 2012. Nesting density of Hermit Thrushes in a remnant invasive earthworm-free portion of a Wisconsin hardwood forest. Wilson Journal of Ornithology 124:375-379.
Loss, S.R., Niemi, G.J., Blair, R.B. 2012. Invasions of non-native earthworms related to population declines of ground-nesting songbirds across a regional extent in northern hardwood forests of North America. Landscape Ecology 27:683-696.
Loss, S.R., Blair, R.B. 2011. Reduced density and nest survival of ground-nesting songbirds relative to earthworm invasions in northern hardwood forests. Conservation Biology 5:983-993.