Understanding Minnesota Brushlands
To some, the term “brushland” describes a wasteland – something that should be cleared and drained in order to be farmed, pastured, or planted to trees. However, a variety of brushland and other open habitat types, ranging from shrub swamp and wet meadow/fen types through relatively open aspen parkland and stagnant conifer bogs, are native plant communities that occur throughout Northern Minnesota. These communities are home to a wide variety of wildlife species, many of which require large areas of open habitat. Brushland communities are usually early successional or “young” habitat types and require periodic disturbances to maintain and sustain them.
History of Brushlands
About 10,000 years ago, as the large glacial lakes of Northwestern and East-central Minnesota slowly dried and finally disappeared, they left large, relatively flat landscapes that were once lake bottoms. The largest was Glacial Lake Agassiz, which covered all of Northwestern Minnesota, Northeastern North Dakota, and extended far in Canada. In East-central Minnesota, the smaller Glacial Lakes Aitkin, Upham, St. Croix, and Duluth left the same land pattern. Historically, forests were rare on these lakebeds due to peaty soils and wet conditions. When the land did dry enough to grow trees, naturally occurring wildfires kept these areas from converting to forest. During the homestead era that began in the late 1800’s many of these lands were ditched in an attempt to drain them for farming. Most of these efforts ultimately failed, and while the ditch networks remain, much of this landscape today is a mosaic of wild and semi-agricultural open land and nonproductive forest. Successful wildfire reduction programs, tree planting, and changes in general land use are resulting in the conversion of many acres of brushland habitat into marginal or stunted forest and decadent, less productive brushlands. As a result, populations of many brushland wildlife species are declining
Many wildlife species have adapted to life in Northern Minnesota’s brushlands. Some species require large areas of open brushland, while others are equally at home in both brushland and forested habitats. Sharp-tailed grouse, white-tailed deer, woodcock, furbearers, and various other game and non-game species all utilize brushland habitats.
The sharp-tailed grouse, or “sharptail” is an obligate brushland species, meaning that it requires large areas of brushland habitat. Unlike its cousins, the ruffed grouse and spruce grouse, sharptails cannot live in typical forests, (sharptails will utilize relatively open forests such as stagnant conifer bogs), and unlike its other cousin the prairie chicken, sharptails in Minnesota do not prosper in brush-free grasslands. The sharptail is native to Minnesota and historically thrived wherever there were natural open landscapes. It reached its peak during the logging and settlement era, when vast areas of northern Minnesota were converted to open land. At that time it was the most common grouse species in Minnesota and hunters harvested up to 150,000 sharptails yearly through the 1940’s. However, harvests have diminished as brushland habitat and sharptail populations have declined, so that today, about 10,000 are taken each year.
Sharptails require large expanses of open habitat with a mix of grass, brush, and small, scattered clumps or “islands” of trees. The larger the open habitat block, the better. The landscape can be any combination of upland and lowland, as long as it is open. During the spring, several males gather on traditional dancing grounds, or leks, and vie for the chance to mate. Usually, the lek is located on the most open and slightly raised piece of ground available. Minnesota Sharp-tailed Grouse Society place observation blinds on select leks each spring, enabling hundreds of people to watch this beautiful and often comical display. In the fall, sharptails often engage in short migrations to open bogs where they spend the winter. Summer foods include insects, berries, clover, alfalfa, and various other native forbs and grasses. Winter foods include the buds and twig ends of bog birch, paper birch, aspen, and various remaining seeds and fruits. Sharptails also utilize small grains, especially buckwheat and oats.
Nongame and Other Wildlife
Minnesota is home to over 600 wildlife species, of which nearly two-thirds are classed as “nongame.” These wildlife species are not hunted, trapped, or fished. Dozens of wildlife species utilize open grass-brush habitats in the northern forest, and many are rare or unique. Some depend on the large open landscapes also required by sharp-tailed grouse, while others use smaller open areas. Some prefer drier areas, some prefer wetter areas, and some can be found in both uplands and lowlands. Although a totally inclusive list is beyond the scope of this brochure, the following is a sample of some of the diverse wildlife species that depend on Northern Minnesota’s brushland habitats. Bird species that inhabit brushlands or open landscapes are more at risk than any other group of species, and some are even on the state’s threatened and special concern lists. These include the yellow rail and sharp-tailed sparrow, both of which require large expanses of sedge lowlands.
Large brushland habitat complexes also attract Eastern meadowlarks and bobolinks, both of which are suffering from general population declines across the Upper Midwest. Another imperiled songbird, the golden-winged warbler, reaches its greatest breeding densities in young forests near open habitats. Uncommon upland sandpipers and the rather common Eastern bluebird frequent brushlands intermixed with old upland pasture or hayland. Northeastern Minnesota’s brushlands are also home to some of the easternmost populations of black-billed magpies, a long-tailed black and white bird common in the mountains and prairies of the West. Grass and brush habitats in lowland areas attract yellow warblers, sedge wrens, sora rails, American bitterns, and even sandhill cranes, which are a close relative of the critically endangered whooping crane. Several of Minnesota’s frog species, including spring peepers and wood frogs, are also common in lowland areas. Great gray owls, uncommon diurnal (day- hunting) short-eared owls, along with Northern harriers or “marsh hawks”, and American kestrels or “sparrow hawks” hunt for the insects and small mammals, such as meadow voles, that abound in grass and brush habitats.
Managing Your Brushlands
Shearing & Mowing
“Shearing” with a bulldozer over frozen ground is often used to regenerate large stands of stagnant brushland. The over-mature brush and trees are sheared off at ground level and vigorously sprout new growth, providing optimum habitat for brushland species for several years. Mowing or chopping stagnant brush with a rotary-axe mower basically accomplishes the same thing, and the shredded vegetation is generally cleaner in appearance immediately following management. In general, shearing is cheaper than mowing, but more effective in areas where the diameter of the brush is smaller (shearing often leaves “whips” or small diameter stems that remain standing in such areas) and drier sites can be mowed at any time during the year (optimal brush control is often obtained in late summer/early fall). Regardless of whether an area is sheared or mowed, the debris will deteriorate naturally and is barely noticeable within 1-2 years. A prescribed burn can be used to further eliminate debris and will help maintain your brushland habitat in favorable condition
Prescribed burning is another method commonly used to manage brushlands. Burning top-kills brush and trees, reduces litter, encourages seed germination, stimulates sprouting, and often improves berry production, thereby providing excellent sources of food for wildlife. Burning is most effective in brushlands that have a mixture of shorter brush and grass. Therefore, prescribed burning is often used to maintain brushland habitat that has been previously sheared or mowed, as it is much cheaper than either mowing or shearing. Prescribed burns are usually conducted in spring or, less commonly, in fall when the vegetation is dormant and dry. A rotation of 2-8 years between burns, depending on the vegetation, should be sufficient to maintain your brushland in favorable condition. Do not be overly concerned about destroying bird nests during your spring burns. The adult females usually escape harm and many will re-nest. The long term benefits of burning far out-weigh any temporary setbacks.
Haying brushland that mainly consists of grasses will help keep the area more open. In areas that are hayed every year, waiting until after the primary nesting season will help reduce bird nest destruction. In addition, scattered hayfields, especially those without nearby trees, provide sharp-tailed grouse with open areas suitable for dancing grounds.
Grazing, particularly in tree-free areas with a mix of grass and brush, can maintain brushlands in a more open condition. Managed rotational or prescribed grazing systems, where livestock is managed to impact areas needing treatment, and removed before the areas are overgrazed, are preferred over season-long unmanaged grazing systems.
If trees surrounding and within brushland habitat complexes are of merchantable size, and are present in sufficient quantity and quality, a timber sale may become a management option. A clear-cut without reserves (no trees left standing) is the appropriate type of harvest scheme in brushland areas. Timber sales provide personal income and result in excellent habitat for various brushland wildlife species.
Food plots are not a replacement for good habitat management; however, food plots consisting of small grains, sunflowers, clovers, or corn are another way to benefit and attract brushland wildlife to your property. Food plots provide concentrated sources of readily available food relished by a variety brushland wildlife including white-tailed deer, sharp-tailed grouse, waterfowl, bear, and sandhill cranes. Basically, a food plot is simply a “fast food restaurant” next to the “health food store”.
Last modified: February 2, 2019