Interleavings: hardwood and coniferous forests rub shoulders in Michigan's Lower Peninsula

Natural History, March, 2002 by Robert H. Mohlenbrock

While driving north from Lansing in Michigan's Lower Peninsula, my wife, Beverly, and I passed the town of Clare, which a billboard proclaimed to be the "Gateway to the North." As if to confirm this, after a few miles the vegetation suddenly began to change. The woods to our south had consisted of broad-leaved hardwood trees--sugar maple, black oak, red oak, white ash--beneath which grew shrubs and wildflowers that required mild summers and moderate rainfall. Now the slender spires of tamarack and balsam fir dominated a scraggly forest, while impenetrable-looking layers of hardy shrubs filled the understory. Flashes of sunlight bounced off pools of water as we passed by, revealing the soggy nature of the forest interior.

In fact, broad-leaved hardwood forests also exist in the north of Michigan's Lower Peninsula, but there they are confined to drier, upland areas. The coniferous forests appear in the lowlands, which are filled with lakes, bogs, and fens. In many places, both of these northern forest habitats can be observed close together. One place where this is evident is the seven-square-mile Rifle River Recreation Area, administered by the Michigan Department of Natural Resources, Division of State Parks and Recreation. There, at the lower elevations but away from boggy depressions, you will also find a moist forest with red maple, American elm, and green ash.

A loop road that begins at the park entrance provides a broad overview of the forests and passes by several of the numerous lakes. Wild turkeys and white-tailed deer may be seen on almost every drive around the park. Waterfowl abound, including herons, egrets, and loons.

For a more intimate experience, hike one of the trails. Pintail Pond Trail will take you from an upland woods to a moist woods to a white cedar swamp and finally to a tamarack bog. Be on the lookout for woodcocks, rabbits, squirrels, raccoons, foxes, beavers, otters, ruffed grouse, and muskrat. And if you go to the park in the first half of June, be sure to visit Grouse Haven Lake, reached by a quarter-mile-long side road off the loop road. In a sandy zone that begins about ten feet back from the shore, colonies of pink lady's-slipper orchids will be showing off their pale, delicate blooms.

HABITATS

Upland woods. Color and texture variations are provided by the soft, bright green needles of white pine, the broad leaves of red oak and black oak, the stark white trunks of paper birch, and the gray trunks of quaking aspen and big-tooth aspen. The leaves of balsam poplar are particularly showy when the wind blows, exposing their rust-colored lower surface. Shrubs and small trees: round-leaved dogwood, hazelnut, bush honeysuckle. Wildflowers: several species of asters and goldenrods.

Moist forest. Red maple, American elm, and green ash provide dense shade, fostering a lush, junglelike growth of mosses and other plants. Wildflowers: false lily-of-the-valley, bluebead lily, cucumber-root, starflower, goldthread (named for its roots), partridge berry.

White cedar woods. White cedar (sometimes known as arbor vitae) grows in fairly flat areas, but within this forest are numerous shallow depressions where water stands for much or all of the year. Other trees are black ash, green ash, and red maple. Mosses and extensive patches of sedges carpet much of the forest floor. Shrubs: shrubby cinquefoil, sweet gale, several species of willows. Wildflowers: false Solomon's-seal, starry Solomon's-seal, pink bog avens, recurved buttercup, one-flowered shinleaf, pink pyrola, grass-of-Parnassus, wild cranberry, creeping wintergreen, twinflower.

Tamarack bog. Tamarack (larch) grows where the ground becomes more saturated and the water in depressions is a little more acidic. This conifer, like the bald cypress and pond cypress of the southeastern United States, is deciduous, losing all of its short, soft needles in the autumn. Smaller trees are bog birch and bog willow. Two species of sedges that form cottony seed masses are called cotton grass. Wildflowers: pitcher plant, rose pogonia orchid, yellow lady's-slipper orchids, Labrador bedstraw.

Robert H. Mohlenbrock, professor emeritus of plant biology at Southern Illinois University, Carbondale, explores the biological and geological highlights of U.S. national forests and other parklands.

For visitor information, contact:
Rifle River Recreation Area
2550 East Rose City Road
P.O. Box 98
Lupton, MI 48635
(989) 473-2258