To support prairie restoration, St. Olaf researchers look at soil bacteria

Rebecca Jirik ’20 (left) and Carly Challgren ’19 take a soil sample for analysis.

Scientists estimate that only about 5 to 10 percent of the original tallgrass prairie that once thrived in the Midwest remains today.

To better support prairie restoration projects, a team of St. Olaf College researchers is thinking small — microscopic, in fact.

Under the guidance of Associate Professor of Biology Jean Porterfield, St. Olaf students Rebecca Jirik ’20 and Carly Challgren ‘19 spent the summer collecting and analyzing soil bacteria samples from local prairie restoration plots to study the results of different prairie restoration methods. They collected the samples from prairie lands belonging to Assistant Professor of Biology and Environmental Studies Diane Angell and her family.

“We’re looking at three different types of prairie in the Northfield area: one that was restored in 2005, one that was restored in 2010, and one that is a remnant prairie that has existed for many years,” Jirik says. “We will be looking at the genes of the microbes in the prairie, specifically four genes that have to do with the nitrogen cycle, to compare the amount of genes present in the soil to the actual expression of the genes. One of these genes is involved in creating a greenhouse gas that could be emitted in the nitrogen cycle and another codes for a protein that releases ammonium, which plants need to grow. We want to learn more about the connections between the nitrogen cycle and different types of prairie.”

Carly Challgren ’19 (left) and Rebecca Jirik ’20 in the laboratory comparing DNA of various soil samples.

Their focus is to gather this data and observations to be used in other restoration and agricultural practices, as well as gain research experience. So far, their findings suggest that there are some genetic and ecological differences between the remnant and restored prairie sections.

This summer research is part of the college’s Collaborative Undergraduate Research and Inquiry (CURI) program, which provides opportunities for St. Olaf students from all academic disciplines to gain an in-depth understanding of a particular subject by working closely with a St. Olaf faculty member in a research framework.

“You learn a lot of transferable skills and lab techniques that can be used beyond soil analysis, so if either Becca or myself decide to go into biomedical lab work or different parts of science research, these are skills that we’re going to need,” Challgren says. “Neither of us see ourselves going into soil research, but these are all things that are going to help us down the road.”

Jirik is on the path to become a genetic counselor, while Challgren is considering the academic, medical, or research field.

Challgren is also gaining a different set of techniques for analyzing soil by working with Professor of Biology and Environmental Studies and Curator of Natural Lands Kathleen Shea on another CURI research project focused on the ecology of the Natural Lands.

“Carly brings those skills to our research and helps us get more ecology type data from our soil, so we can analyze everything,” Porterfield says. “This type of project at a big university would probably be more specialized in just the genetics, but here at St. Olaf the place we analyze the soil is three doors down from the place we analyze the genetics, so we have that ability to apply more types of skills to the same project.”

“A highlight for me was when my other research team and this team went out together to collect soil samples,” Challgren says. “It was just a cool bonding experience to bring that aspect of my research in with this other part, and we all blended really well and were efficient in getting everything done to help bring a different project to a separate end.”

Carly Challgren ’19 (right) examines the soil sample that Rebecca Jirik ’20 extracted.