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Seney-Tahquamenon Sand Plain

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About the Seney-Tahquamenon Sand Plain

The Seney-Tahquamenon Sand Plain is a region in the interior of Michigan's Upper Peninsula, the easternmost region that does not border one of the Great Lakes. It is covered in extensive peaty wetlands.

This region is a broad lake plain with a mostly flat landscape broken by occasional beach ridges or sand dunes. This area is covered by thick sandy glacial drift, with the bedrock 100-200 feet below the surface across most of the region. The water table here is permanently high and the area as a whole is poorly drained. The water from this region slowly drains out of this region, mostly to the east, forming the source of many of the rivers of the upper peninsula. Soils here tend to be formed of varying mixtures of coarse sand and peaty, organic muck. Pure sandy soils are limited to ridges, most common in the west of this region, and are excessively drained.

This region was originally covered in extensive areas of swamps and peat bogs dominated by conifers, including tamarack (Larix laricina), black spruce (Picea mariana), northern white-cedar (Thuja occidentalis), balsam fir (Abies balsamea), and eastern white pine (Pinus strobus). The wettest sites supported stunted growth of tamarack and black spruce. Throughout these regions there was also a boggy ground cover including bog rosemary, cranberries, laurel, sphagnum mosses, and blueberries. Dry sand ridges supported jack pine (Pinus banksiana) and red pine (Pinus resinosa) on the more fire-prone sites, and northern hardwood forests on the more lake-moderated sites protected from fire, with American beech (Fagus grandifolia), sugar maple (Acer saccharum), white pine, and eastern hemlock (Tsuga canadensis). There were some dry, fire-prone outwash plains dominated by jack pine. Seasonally-moist areas supported red pine, white pine, and large-tooth aspen (Populus grandidentata).

Beavers played an important role in the hydrology of this region, causing local flooding. Fire was common, both on peatlands and dunes. The steepness of the dunes limited the intensity of the fires, contrasting with the drier outwash plains which had more severe fires.

Widespread logging in the swampy areas has reduced the portion of conifers; these areas are now a mix of second-growth conifers and hardwoods, including birch, aspen, and red maple (Acer rubrum). Boggy sites support more-or-less similar vegetation. There is significant protected land here. Seney National Wildlife Refuge is located within this region, and Hiawatha National Forest encompasses land both here and outside this region to the north. This area is sparsely populated and has seen little development; it has some of the largest and least-altered wetlands in the broader region.

Over its length, this area is bordered to the north with the Grand Marais Lakeshore, a region that tends to be better-drained and more lake-moderated, and to the south by the Menominee-Drummond Lakeshore, also better-drained and with a more lake-moderated climate, and a greater diversity of topography soil types. At the far east of this region there is a border with the Rudyard Clay Plain, another low-lying poorly-drained area that contrasts with this one because of its clay soils.

References

1. Omernik, J.M., Bryce, S.A. "Michigan: Level III and IV Ecoregion Descriptions / Mapping Issues", US EPA (2007) Web.

2. Albert, Dennis A. "Regional landscape ecosystems of Michigan, Minnesota, and Wisconsin: a working map and classification.", General Technical Report NC-178, U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station, St. Paul, MN (1995) Web.