Aspen

Most Wisconsinites know aspen as “popple.” The name may come from the Latin term Populus, the genus in which big-toothed aspen and quaking aspen are classified. Both big-toothed and quaking aspen yield valuable forest products, including pulp for paper, chips for strandboard, and biomass for generating electricity. Especially when young, aspen forests provide food and homes for a broad range of reptiles, birds, and mammals.

To learn more about managing aspen to help wildlife, consult Best Management Practices for Woodcock and Associated Bird Species.

Also see Best Management Practices for Golden-winged Warbler Habitats in the Great Lakes Region, including the supplement Deciduous Forests. A good general reference is A Landowner’s Guide to Woodland Wildlife Management.

Mature aspens can be harvested to create young forest that attracts and supports a great abundance and variety of wildlife./C. Fergus

Tiny airborne seeds let aspen quickly reforest areas where human-caused or natural disturbances, such as even-age logging, storms, or fire, remove the overstory trees. Aspen also sprouts from its roots, underground networks called clones, that can cover acres. When young (up to around 20 years), a stand of aspen can be very thick. Yet plenty of other plants grow among the crowded trunks, because the trees’ trembling foliage is relatively open, letting a good amount of light reach the forest floor.

This rich shrub and herb community yields abundant fruits and insects. Many kinds of birds breed and nest in and beneath young aspens, including woodcock, ruffed grouse, wild turkeys, and songbirds. In summer, songbirds (including ones that breed in older forest) congregate in dense, food-rich aspen stands, where their fledglings can find protection from predators, grow quickly, and put on fat before migrating south in autumn. Deer and moose browse on aspen regrowth, and beavers cut and feed on the young trees.

Aspens start to die out after about 50 years, at which point other longer-lived hardwood trees take over. With age, aspens' underground root systems gradually

become less vigorous and less able to send up new trees should a windstorm, fire, or logging operation remove the standing timber. Today, there’s an overabundance of old aspen and not enough young aspen in many parts of Wisconsin. Forest inventory data predict significant declines in the Upper Midwest in the amount of aspen (and also paper birch, balsam fir, and jack pine, three other quick-growing, short-lived trees) unless more landowners manage their woodlands in ways that favor these young forest species.

The Wisconsin Young Forest Partnership advises landowners on how to harvest aspen to create young forest and improve habitat for wildlife.

Young aspens and diverse other trees, shrubs, and plants spring up following an even-aged timber harvest at Navarino Wildlife Area./C. Fergus

Landowners can use commercial logging to regenerate older aspen while gaining income. Cutting aspen spurs it to grow back densely. (It’s best to harvest trees after leaf-fall in autumn, or in winter, when aspens store their energy in their root systems, ensuring maximum sprouting during the following growing season.)

Other management techniques to restore or promote aspen include noncommercial timber harvests, in which pole-stage trees are sheared or cut and left on the ground; and controlled burning. A carefully designed management plan will include keeping important features, such as dead trees (snags), to increase the diversity of birds and other wildlife. Be sure to leave some mature “legacy” trees standing, as songbirds will use them as singing perches and for foraging.

Interested landowners can see aspen restoration on Chequamegon-Nicolet National Forest in northern Wisconsin, and on any of the other public-lands habitat demonstration projects listed on this website (scroll down on this list of projects to find areas to visit).

Mourning warblers breed in dense young forest in northern Wisconsin./T. Berriman

Hardwoods

Shrub Wetlands

Old Farmland