Turtle Mountain Sphagnum Bog

Nestled in among the aspen on the west side of the Turtle Mountains lies the only known Sphagnum bog in North Dakota. Although bogs may be occasionally observed in other areas such as coniferous forests of northern Minnesota and Canada, that is not the case in North Dakota. And although other sites in the state may be called bogs, such as the Denbigh bog and Pettibone bog, they are actually fens. Fens and bogs differ in many significant ways, including that water moves through fens. Not so with a bog.

Sphagnum bogs generally occur where a floating mat of Sphagnum moss grows and forms a cover over a protected body of water. If a small mat of floating material forms on the shoreline, for example the roots and rhizomes of adjacent plants, Sphagnum moss may colonize the floating mat. The mat will float, and of course be very wet. Unless it is destroyed by waves or ice action, the floating mass of Sphagnum may continue to grow, accumulate organic matter or peat, and eventually form a sort of blanket on the body of water.

This floating blanket of Sphagnum changes the ecology of the wetland in many significant ways. Perhaps the most interesting thing about Sphagnum is that it has the amazing ability to absorb cations and release hydrogen ions back into the water. It makes the water more acidic! The acidity of the water may become similar to that of vinegar or lemon juice. As a result few organisms can live in the water in and under the Sphagnum mat. There is no decomposition, few available nutrients, and virtually no oxygen.

Few plant species can live on Sphagnum bogs, and many are uncommon or rare. The vegetation of Sphagnum bogs is often dominated by plants of the heath family such as wild cranberry or Labrador tea. Many of the plants occupying the Turtle Mountain bog are quite unique and rare to the state. The list includes nine rare species, and the state’s only known population of the carnivorous round-leaved sundew.

The Turtle Mountain Sphagnum bog is undoubtedly one of the most unique plant communities in the state. Its location, as you might expect, is a closely guarded secret.

Chuck Lura

Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.