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The 2017 Seventeenth Annual UMM Undergraduate Research Symposium (URS) celebrates student scholarly achievement and creative activities. Students from all disciplines participate in the URS. Types of presentations include posters, oral presentations, and short or abbreviated theatrical, dance, or musical performances. 

Presentations are accompanied by discussions and multimedia.


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Saturday, April 22 • 10:00am - 12:00pm
Environmental Factors Drive Variability in Earthworm Populations Sampled Through Time at Six Sites in Western Minnesota

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Prior to European settlement in the mid-1800s, Minnesota’s prairie and forest biomes were free of invasive Eurasian earthworms. Since then, the earthworms have spread into many parts of the state, but the extent of this invasion is still poorly documented. Here we report the characteristics and relative abundances of earthworm species from six sites spread across a 400 km transect following the prairie-forest ecotone in western Minnesota. At these six sites, we sampled earthworms and vegetation at 12 plots, representing a variety of microenvironments, using the hot-mustard extraction technique. Earthworms were subsequently identified and measured to calculate total biomass. While most studies only sample once to obtain a snapshot in time, we have documented the same 144 plots three times from 2012-16. Populations varied with time, however earthworms found in one sample roughly predicted the next sample, two years later (R2=0.2-0.45). High earthworm populations were correlated with high soil moisture, increased pH, decreased soil litter and organic layers, and low ground-level light. Overall, the two sites furthest into the historical prairie had earthworm populations that declined with time, while the three sites within the forested side of the prairie-forest ecotone had increased populations from 2012-2016. The sixth site remains relatively uninvaded. Overall, we have found evidence that the spread of earthworms in Minnesota may be limited by a drying and warming climate

Saturday April 22, 2017 10:00am - 12:00pm
Student Center, Oyate Hall 600 E 4th St., Morris MN 56267