Written by Michelle Homann

Posted April 2025

This past winter, we only had two snow events that were substantial enough to apply snow reduction and addition treatments out at Mounds View Grassland. This is where we study tallgrass prairie plant community responses to snow depth in collaboration with the Midwest Climate Adaptation Science Center. Lily Meisel led the first trip on December 22, 2024 and did a fantastic job organizing newly hired students to get all 64 1 m2 treatment plots shoveled down to 2 cm snow depth in one day. Records from the first shoveling trip show that some areas had up to 25 cm (nearly 10 inches) of accumulated snow before treatments were applied!

(above) Undergraduate students shoveling at Mounds View Grassland after a substantial snow event in December. Photo by Wen Zhang.

We had one other snow event that exceeded 10 cm (4 inches) of snow, which is our minimum accumulation to apply snow reduction and addition treatments. A crew led by Michelle Homann went out on February 16, 2025 and found that, in some areas, snow had accumulated up to 38 cm (almost 15 inches). It was a windy but sunny day, and the work went quickly despite the deep snow.

(above) Post-treatment photo with reduced snow and added snow treatments in February. PVC poles are approximately 1m tall. Photo by Michelle Homann.

Studying winter climate change through manipulative experiments can be challenging because a lack of snow to manipulate has become increasingly common. In the seven winters since this experiment started in 2016, we have had, at most, 6 winter snow events in a single year that exceeded 10 cm of accumulated snow. Those snowfalls happened between January and February 2019, and we’ve seen fewer snow events per year since. From January 2022 to February 2025, we have only had 5 TOTAL snowfall events that exceeded 10 cm – only one to two per year. 

Reduced winter snow depth has a few important implications, which we study in the Damschen Lab. Reduced snow means reduced insulation of the soil surface and a loss of the “subnivium,” a space at the interface of snow and soil that maintains stable temperatures around 32°F (0°C). The subnivium is maintained not just through the presence of snow, but through a combination of snow depth and density – a balance that is at risk as winters warm. The implications of subnivium degradation or loss include colder and more variable soil temperatures, which could have widespread implications for plant cold tolerance, re-emergence, and growth strategies.

Leaf litter (dead plant material from previous years) can serve some similar functions to snow by acting as insulation and a barrier for evaporation, increasing temperature stability and moisture at the soil surface. Disturbance type and timing can alter litter depth and density, so how management decisions, like mowing and burning, interact with winter conditions is important to understand, as well. This spring, we will be collecting plant material in early spring to test how burning in fall, mowing in fall, burning in spring, or not applying any disturbance might influence the cold tolerance of prairie plants. The results will give us some insight into the management practices that best prepare tallgrass prairie plant communities for changing winter conditions. 

(above) Plant samples prepared to test the temperature at which ice forms in the plant tissue. Keep an eye out for more about our work regarding plant tissue cold tolerance in future posts!

Stay tuned for more results from this work! We will be sharing blog posts here (on our website) biannually throughout the next few years to keep you updated on our research progress, highlight new findings and stellar students, and provide access to communication materials on best management practices.