After a growing season filled with rain and mosquito bites, the Arboretum natural areas crew has been busy preparing for winter. Tree thinning and seed collection set the stage for future restoration projects. In this report, we highlight some of our most satisfying current projects.
Roaring chainsaws and fallen trees were a common scene this fall. Since early October the crew has been restoring the oak savanna landscape that was historically found on the Grady Tract. From 2013–17, forestry mowing on eighty acres removed a thick tangle of buckthorn, honeysuckle, and Oriental bittersweet, revealing widespread maple, black and red oak, black cherry, and black walnut trees. In a healthy oak savanna ecosystem, fire would have naturally kept the majority of those individuals from establishing, but the absence of fire over the decades allowed them to grow and spread. Many of the trees were removed following the forestry mowing, but not all. So we have continued working to accomplish what fire would have—removing those trees so that more fire-tolerant species such as bur and white oaks can flourish. We also hope that the removal of these trees facilitates better prescribed burns and more wildflower diversity in the future.
We are also excited to be restoring and expanding a small hill prairie at Lodde’s Mill Bluff, one of our eleven outlying properties, located in Sauk County near the Wisconsin River. Lodde’s is a twelve-acre site, mostly forested, with the exception of a few small pockets of remnant prairie near the top of the bluff, almost three hundred feet above its base. In the absence of fire, eastern red cedar has encroached on much of the existing prairies, so we have been removing them to bring in more sunlight for the prairie plants and existing bur oaks. The plants, including prickly pear, butterfly milkweed, purple prairie clover, lead plant, little bluestem, and candle anemone, will benefit from the increase in sunlight following cedar removal. In the future, we hope to introduce prescribed burning to maintain and expand the prairie.
A big part of our job is collecting seed to help fill in our current restoration areas. Seed collection begins in May and it continues throughout the fall. This past season we collected seed from over eighty species gathered from the main Arboretum property and several outlying properties. Seed collecting is essential for our restoration projects and allows us to add more diversity to our landscapes. Once the seeds are collected, we lay them out to dry in our seed room. After the seed is dried, we run it through a hammer mill to separate the seed from the rest of the plant material. The seed is weighed and divided into seed mixes that are appropriate for specific habitats, including a range of prairie types, savannas, and woodlands. We hope to finish making our different seed mixes by early winter and spread it throughout our restoration sites before the first major snowfall.
Even though the growing season has come to a close, our work is far from over. Clearing undesirable trees and making seed mixes help lay the groundwork for many of our other restoration activities. It is often cold and physically tiring, but worth it when spring comes around. On top of all of the restoration activities, the crew has also been repairing service roads, removing snow, and preparing our equipment for the winter ahead. If you have time, please check out our work in the Grady Tract and ask us questions if you see us out there. We love talking to visitors about restoration and the work we are doing.
—Isaac Bailey, Tom Bresnahan, and Lance Rudy, Arboretum restoration technicians