Big Bog State Recreational Park

Upper Red Lake Area Association

Ludlow Island Patterned Peatlands
Big Bog State Recreation Area
Cindy Lueth, April 2002

Introduction
The Big Bog State Recreation Area (Big Bog SRA) established by the 2000 Legislature, is the newest member of Minnesota's state park system and perhaps one of the most unique. It is located in northern Minnesota's Red Lake peatland close to the town of Waskish. Big Bog SRA contains a campground and day use area in its southern unit on Red Lake, and 9000 acres of peatland north of Red Lake and west of Minnesota Highway 72 in the northern unit.

The Red Lake peatland lies within the level landscape of glacial Lake Agassiz. The glacial lake bed, with less than 10 feet of elevation change (1), allowed the Red Lake peatland to form the largest continuous peatland complex (1500 km2 ) in the northern contiguous United States (2). Peatlands form in two ways: filling in from the sides of watery lake basins or building up from almost flat, poorly drained land with no lake (Red Lake peatland) (3). Both types of peatland require cooler temperatures and plenty of moisture. The combination of cool temperature, moisture and poor drainage creates a system where vegetation does not decay quickly or completely and accumulates in layers of partially decomposed material called peat. The Red Lake peatlands began to form about 3000 years ago and are an average depth of 10 feet of 
peat (4).

Importance of Big Bog SRA to State Park Experiences in Minnesota
The landscape of the Red Lake peatlands is unusual and at the scale at which it occurs, it is unique in the contiguous United States. When viewed from above, distinct symmetrical vegetation patterns are seen that resemble landforms more often found in aquatic settings: river channels, islands and riffles (5). The landforms each have a narrow range of water chemistry (pH) and distinct vegetation assemblages growing above the accumulated peat. Research suggests water flow below the surface is responsible for the formation of the landforms (5). This type of peatland is referred to as a "patterned" peatland.
The Red Lake patterned peatland contains raised bogs, fen water tracks, small peat ridges with strips of vegetation oriented perpendicular to water flow in the water tracks (strings) and water pools within water tracks, also perpendicular to water flow (flarks). Raised bogs are raised in profile, which prevents upland waters from draining onto them. Spruce trees growing on the crest of northern Minnesota's raised bogs radiate out to the edges and are readily seen in aerial photos. Water tracks are areas of mostly treeless vegetation that resemble river channels from above. Water on the surface of vegetation in the water tracks may or may not be visible. Minnesota's most pronounced water tracks are found in the Red Lake
peatlands (5). 

Each of the patterned peatland landforms (raised bogs, fen water tracks, strings, flarks) has slightly different vegetation associated with it (6). Bog vegetation is dependent on rainwater for nutrients; therefore the range of bog-tolerant vegetation is narrower than that of fens. Fen plants use ground water that has percolated through mineral soil and is less acidic than bog water. Black spruce, capable of very slow growth, are the only trees readily found in the mineral poor radiating bog forests and bog islands. Eight of Minnesota's rare plants are primarily found in the patterned peatlands and about 40% of Minnesota's listed species are wetland plants (40% of 174 plants) (7)(8). 

Mosses and bogmosses (Sphagnums) are the principle peatland vegetation and form an almost continuous mat of surface vegetation above the peat accumulations. 164 species of mosses and bogmosses have been identified in Minnesota peatland sites (9) including some previously thought to be extinct.

As briefly outlined in the preceding paragraphs, the glacial Lake Agassiz patterned peatlands is an area of unique landforms, many rare plants and intriguing relationships between landforms, vegetation and hydrology. The 2000 Minnesota State Park System Land Study identified a need for resource preservation in the Agassiz region, especially in open sphagnum bogs, black spruce bogs, peat bogs, white cedar swamps, and lake beaches (10). All these features are found within the boundaries of Big Bog SRA.


Development Issues on Ludlow Island
In order to retain the "wilderness" characteristics of the Red Lake peatland, the Big Bog SRA draft management plan provides for minimal development on the northern unit of the SRA. Development will center on Ludlow Island, an area of glacial beach ridge adjacent to Highway 72. The plan calls for a boardwalk trailhead that includes boardwalks, picnic shelter, parking, toilets, information kiosk and hiking trails on Ludlow. Interpretation of peatland natural history will be an important feature of the boardwalks and information kiosk. Provision is made for limiting access to areas of the bog for ecological preservation
reasons (11). 

Park's staff identified a boardwalk (or bogwalk) alignment that takes visitors from an abandoned gravel pit pond on Ludlow Island north to a patterned fen with a water track containing strings and flarks. This two mile walk brings visitors through several wetland systems including a pond, lowland brush, black spruce bog forest, judicial ditch with non-bog vegetation, fen water track, strings and flarks. 

The potential for disturbing fragile natural plant communities is high depending on how development is managed. There is a known population of rare sedge on Ludlow Island. Care should be taken to avoid that location for road or parking improvements. Once Ludlow road, parking and trail footprints are proposed, all alignments must be carefully assessed for rare plant species.

There are no known populations of rare species along the proposed bogwalk alignment. However, the likelihood that such species will be encountered is high. Known populations of the following rare species exist in close proximity to the SRA boundaries: Arethusa bulbosa (Dragon's-mouth,) Carex elixis (coastal sedge,) Drosera anglica (English sundew,) Juncus stygius (bog rush,) Rhynchospora fusca (sooty-colored beak rush,) Xyris montana (Montana yellow-eyed grass.) (12) Care should also be taken to avoid disturbing the yellow rail, a rare bird known to occur in the area. Additionally, it is likely that some rare species not yet found in the immediate area will be encountered as more botanists have easier access to these sphagnum systems especially as the black spruce bog forest is the preferred habitat for several uncommon species. 
In addition to rare species considerations, care needs to be taken to avoid wetland impacts, both on Ludlow Island and out in the peatland. Consideration should be given to bogwalk materials that minimize impact to the sensitive patterned peatland ecosystem. In particular, a walk that allows light to penetrate below the walk avoids creating a water channel devoid of the current vegetation. This is especially critical in the bog and fen areas with low brush components and on both sides of the judicial ditch. Several peatland plant species exist on a very fine chemical gradient; very small changes in water chemistry could alter the existing plant communities. Using a wooden walkway close to the judicial ditch will create a water channel that will intermix with the ditch water. Subtle changes in the hydrology in this ecosystem could result in enough of a water chemistry change to alter the composition of the existing plant communities along the walkway. Below is a table showing the water chemistry of some of the rare peatland plants (7):
Species pH Ca (mg/1)

Compressing the peatland mosses both by foot traffic and motorized vehicles should be avoided, especially in areas visible to visitors. Aerial photos in The Patterned Peatlands of Minnesota clearly show vehicle tracks remaining 3 years after their use and caribou trails visible after many years. 

Conclusion
Northern Minnesota's patterned peatlands, rich in uncommon landforms, rare and unusual plants and unique hydrology is an excellent addition to Minnesota's State Park System. Walkways allowing visitors access to the peatland provide opportunities to educate the public on the importance of peatlands as well as increasing access for researchers. Such development in the very fragile peatland must be done carefully and with constant consideration of long-term impacts. 


References

1. Sansome, C. J.,1983. Minnesota underfoot, a guide to Minnesota's geology. Stillwater, MN: Voyager 
Press.
2. Janssens, J. A. and P. H. Glaser, 1986. The bryophyte flora and major peat-forming mosses at Red 
peatland, Minnesota. Can. J. Bot. 64:427-442.
3. Wright, H. E. Jr., 1992. Introduction In The patterned peatlands of Minnesota. Wright, H. E. Jr., B. 
A. Coffin, & N. E Aaseng, eds. Minneapolis: University of Minnesota Press.
4. Tester, J. R., 1995. Minnesota's natural heritage, an ecological perspective. Minneapolis: University of Minnesota Press.
5. Glaser, P. H., 1992. Peat landforms In The patterned peatlands of Minnesota. Wright, H. E. Jr., B.
A. Coffin & N. E. Aaseng, eds. Minnespolis: University of Minnesota Press.
6. Glaser, P. H., 1992. Vegetation and water chemistry In The patterned peatlands of Minnesota. 
Wright, H. E. Jr., B. A. Coffin & N. E. Aaseng, eds. Minneapolis: University of Minnesota Press.
7. Glaser, P.H., 1992. Rare vascular plants In The patterned peatlands of Minnesota. Wright, H. E. Jr., 
B. A. Coffin & N. E. Aaseng, eds. Minneapolis: University of Minnesota Press.
8. Coffin, B. A. & L. Pfannmuller, eds., 1988. Minnesota's endangered flora and fauna. Minneapolis: University of Minnesota Press.
9. Janssens, J. A., 1992. Bryophytes In The patterned peatlands of Minnesota. Wright, H. E. Jr., B. A. Coffin & N. E. Aaseng, eds. Minneapolis: University of Minnesota Press.
10. Minnesota State Park System Land Study, 2000.
11. Draft Big Bog State Recreation Area Management Plan, 2002. Minnesota DNR, Division of Parks and Recreation.
12. Minnesota DNR Ecological Services data.