This year, we’re turning six acres of monoculture soybean fields in the Upper Arb into prairie ecoystems. Are you curious about the process?
The prairie plantings in the Arb host 70-80 species. Before the 1970s, most of the 880 acres that are now the Arb were the corn, soybean, and clover fields of local farmers. The environmental movement of the ‘70s created a new conservation ethic at Carleton, and a group of students attempted to transplant a chunk of prarie sod (from a prairie remnant) into the Lower Arb. However, they didn’t know that roots of most prairie grasses go at least 3 feet into the ground, so when they cut off the first six inches, not much survived.
In the 40 years since the project began, Carleton has been refining its technique for transforming farmland into prairie. Learning to mimic natural processes is a new science, because in the past, the goal of land management science has been to change the land to suit human needs, such as for farming.
The first step to restoring prairie is collecting the seed from prairie remnants, which are rare. Seed collecting starts in June, when the first prairie plants make seeds, and goes through October.
Prairie seed-collecting is very time-intensive. The seed is dried in the Arb office, separated from the plant (like corn from the cob, for example), mixed together, and sprinkled on the field. Prairie seeds are planted late in the fall. In the first year, most prairie plants only grow a few inches high- it takes a long time to reach the height of 4-5 feet of the grass in the Lower Arb. In the first few years, it’s hard to judge how the prairie is developing.
Each plant grows in its own way- some seeds have a long dormant period underground, some aren’t identifiable because they don’t bloom for five years or more. Recreating natural prairie requires knowledge of the characteristics of each species and their relationships to each other, and is a trial-and-error process. Carleton’s prairie is one of the best in the area, and what we learn about restoration here contributes to the larger prairie restoration movement across the country.
Emma Rapperport ’13,
for the Cole Student Naturalists