The snow from our second major April storm is only a recent memory. For Madison, it was the second snowiest April on record. We were only one day shy of the previous record for the longest period since January 1 before having a day above 60 degrees. Overall, it will be among the coldest, if not the coldest, Aprils on record. Everyone’s morale is much higher now that spring has finally arrived.
The long wintry weather was beneficial for Arboretum restoration projects, however, as the land care crew had an extended season for clearing invasive trees and brush. Starting in September, the clearing season was one of our most successful (and longest) in some time, with many projects conducted at the Arboretum and outlying properties.
The crew finished the 4-acre area of Skunk Cabbage Wetlands and Wingra Woods I wrote about in the January newsletter, where they logged close to 500 hours. That was our biggest accomplishment of the winter, and the feedback has been very positive. (Many thanks to everyone who provided baked goods to the crew when they were in the field working hard on those cold winter days!) We got a prescribed fire through part of the clearing in March, so it will be fun to watch how the area responds.
The crew also focused time and energy removing invasive European alder trees. Old management records suggest the European alder was mistakenly thought to be the native tag (or speckled) alder shrub and planted during the Arboretum’s early years. As a result, there are numerous stands scattered around the property. The crew removed many small trees from the southern part of Teal Pond Wetlands as part of follow-up to the major clearing done there in 2013. In addition, while Marion Dunn Pond was frozen, they removed trees (and buckthorn) from the pond’s island. And they removed European alders, as well as large buckthorns and honeysuckles, along Arboretum Drive adjacent to Lake Wingra. Native trees and shrubs remain, and in the future we hope to partner with the WDNR on a shoreline project to improve habitat for fish and other wildlife by adding woody structures to the water. These may include strategic tree drops or anchored bundles of trees and branches—habitat features that are often lacking in urban lakes.
This winter’s cold froze the ground well, and snow cover was never very deep, so we had a good protective buffer (to prevent soil disturbance) that made it possible for us to get our tractor and large rotary mower into places we might otherwise worry about driving. Brush invasion in the prairies, especially from native species such as gray dogwood and smooth sumac, requires frequent attention, and mowing with the tractor allows us to clear large areas in a short time. We focused on Curtis and Greene prairies, mowing 7 and 4.5 acres in those prairies, respectively.
The lack of snow throughout much of winter made it easier to treat thousands of mowed stumps and stems with herbicide, and the number of resprouts should be minimal this year. However, we will monitor the mowed areas during the growing season to look for resprouts and new growth, and we will spot treat with herbicide as necessary to help keep down the brush invasion.
In February, we hired Tallgrass Restoration LLC for two days of forestry mowing at Faville Prairie in Jefferson County. They mowed about 8 acres of invasive brush from the remnant prairie portion of the property. The mowing was made possible by funding from a Natural Resources Foundation of Wisconsin C.D. Besadny Conservation Grant (more on this project in a future article). Our crew spent a morning there treating stumps with herbicide after the mowing. Our crew also spent time at another outlying property, Pasqueflower Hill on the west side of Madison, clearing brush and applying herbicide to cut stumps and stems. That was follow-up to larger-scale tree and brush clearing done in 2012 and 2014. We hope to conduct a prescribed fire there this spring.
Additional winter projects included clearing along the west end of Arboretum Drive, in conjunction with work Arboretum garden staff was doing nearby, to remove buckthorn, honeysuckle, and Oriental bittersweet. And selective thinning of oak trees on the northeast corner of Greene Prairie, where it was becoming overgrown, should give that area a more open oak savanna and prairie structure.
I would like to thank everyone who helped with the clearing projects, especially my four land care crew members who worked through an extra-long season of frigid temperatures, flat tires, wet feet, huge vine-tangled multi-stemmed buckthorns, and a finicky wood chipper—among other challenges—but forged ahead to finish with a really successful season. As you visit the Arboretum this year you will notice the improvements!
—Michael Hansen, Arboretum land care manager