Southern Wet Meadow
Southern wet meadow is an open, groundwater-influenced (minerotrophic), sedge-dominated wetland that occurs in central and southern Lower Michigan. Open conditions are maintained by seasonal flooding, beaver-induced flooding, and fire. Sedges in the genus Carex, in particular tussock sedge (Carex stricta), dominate the community. Southern wet meadow, commonly referred to as sedge meadow, also occurs in Iowa, Illinois, Indiana, Minnesota, North Dakota, Wisconsin, and Ontario.
County Distribution Map
Global Rank: G4? - Apparently secure (inexact)
State Rank: S3 - Vulnerable
Southern wet meadow occurs on glacial lakebeds, lakeplains, and in depressions on glacial outwash and moraines. The community frequently occurs along the margins of lakes and streams, where seasonal flooding or beaver-induced flooding is common.
Southern wet meadow typically occurs on neutral to strongly alkaline organic soils (i.e., sapric to hemic peat), but saturated mineral soil may also support the community. Because of the calcareous nature of the glacial drift in the regions where southern wet meadow occurs, its soils typically contain high levels of calcium and magnesium.
Water levels in southern wet meadow may fluctuate seasonally, reaching their peak in spring and lows in late summer, but typically remain at or near the soil’s surface throughout the year. The structure of southern wet meadow is largely influenced by tussock sedge, which forms large tussocks up to 0.5 m high on which many additional species successfully establish above the zone of seasonal inundation. Community structure may depend on a consistently high water table as the tussocks of Carex stricta rapidly decompose when water levels are reduced by tiling. In addition to seasonal flooding, beaver-induced flooding also maintains open conditions by killing encroaching trees and shrubs.
Southern wet meadow is a fire-dependent natural community. By reducing leaf litter and allowing light to reach the soil surface and stimulate seed germination, fire can play an important role in maintaining southern wet meadow seed banks. Fire plays a critical role in maintaining species richness by creating open microsites for small species. Another critically important attribute of fire is its ability to temporarily reduce shrub and tree cover.
In the absence of fire or beaver-induced flooding, all but the wettest sedge meadows typically convert to shrub-carr and eventually swamp forest. Prolonged flooding may also create new southern wet meadows by killing trees and shrubs of swamp forests and shrub-carrs, thus allowing shade-intolerant wet meadow species such as tussock sedge to become established.
Southern wet meadow is typically dominated by tussock sedge. Because its roots form large hummocks or tussocks, the species is responsible for the community’s hummock and hollow structure. As the shaded areas between tussocks are often covered with standing water and leaf litter, many of the shorter species inhabiting sedge meadows grow almost exclusively from the sides or tops of Carex stricta tussocks. Additional common sedges include Carex aquatilis, C. comosa, C. bebbii, C. hystericina, C. lacustris, C. pellita, C. lasiocarpa, C. prairea, C. retrorsa, C. sartwellii, C. stipata, and C. vulpinoidea. The most dominant grass species in southern wet meadow is bluejoint grass (Calamagrostis canadensis), sometimes occurring as a codominant with tussock sedge. Other common grasses include fringed brome (Bromus ciliatus), fowl manna grass (Glyceria striata), marsh wild timothy (Muhlenbergia glomerata), leafy satin grass (M. mexicana), and fowl meadow grass (Poa palustris). A wide variety of wetland forbs and several ferns occur in southern wet meadow, including swamp milkweed (Asclepias incarnata), marsh bellflower (Campanula aparinoides), water hemlock (Cicuta bulbifera), swamp thistle (Cirsium muticum), common boneset (Eupatorium perfoliatum), joe-pye-weed (Eutrochium maculatum), rough bedstraw (Galium asprellum), marsh pea (Lathyrus palustris), northern bugle weed (Lycopus uniflorus), tufted loosestrife (Lysimachia thyrsiflora), clearweed (Pilea pumila), water smartweed (Persicaria amphibia), Virginia mountain mint (Pycnanthemum virginianum), great water dock (Rumex orbiculatus), common arrowhead (Sagittaria latifolia), common skullcap (Scutellaria galericulata), Canada goldenrod (Solidago canadensis), late goldenrod (S. gigantea), swamp goldenrod (S. patula), smooth swamp aster (Symphyotrichum firmum), swamp aster (S. puniceum), purple meadow rue (Thalictrum dasycarpum), marsh St. John's-wort (Triadenum fraseri), marsh fern (Thelypteris palustris), and sensitive fern (Onoclea sensibilis).
Muskrat (Ondatra zibethicus) commonly build lodges in southern wet meadows, which when abandoned are used by Canada geese (Branta canadensis) as nesting sites. Sandhill cranes (Grus canadensis) and marsh wrens (Cistothorus palustris, state special concern) also use the community for nesting habitat. Beaver help maintain open conditions through dam building and subsequent flooding and also through herbivory of shrubs and trees.
- Gentianella quinquefolia (stiff gentian, state threatened)
- Mimulus alatus (wing-stemmed monkey flower, presumed extirpated from Michigan)
- Pycnanthemum muticum (broad-leaved mountain mint, state threatened)
- Acris crepitans blanchardi (Blanchard's cricket frog, state special concern)
- Ambystoma texanum (smallmouth salamander, state endangered)
- Asio flammeus (short-eared owl, state endangered)
- Botaurus lentiginosus (American bittern, state special concern)
- Calephelis mutica (swamp metalmark, state special concern)
- Circus cyaneus (northern harrier, state threatened)
- Cistothorus palustris (marsh wren, state special concern)
- Clonophis kirtlandii (Kirtland’s snake, state endangered)
- Emydoidea blandingii (Blanding’s turtle, state special concern)
- Euphyes dukesi (Dukes’ skipper, state threatened)
- Meropleon ambifusca (Newman’s brocade, state special concern)
- Neoconocephalus lyrists (bog conehead, state special concern)
- Neoconocephalus retusus (conehead grasshopper, state special concern)
- Neonympha m. mitchellii (Mitchell’s satyr, federal/state threatened)
- Nerodia erythrogaster neglecta (copperbelly watersnake, federal threatened and state endangered)
- Oarisma poweshiek (Poweshiek skipperling, state threatened)
- Orchelimum concinnum (red-faced meadow katydid, state special concern)
- Orchelimum delicatum (delicate meadow katydid, state special concern)
- Papaipema cerina (golden borer, state special concern)
- Papaipema maritima (maritime sunflower borer, state special concern)
- Papaipema speciosissima (regal fern borer, state special concern)
- Paroxya hoosieri (Hoosier locust, state special concern)
- Phalaropus tricolor (Wilson’s phalarope, state special concern)
- Rallus elegans (king rail, state endangered)
- Sistrurus c. catenatus (eastern massasauga, federal candidate species and state special concern)
- Spartiniphaga inops (spartina moth, state special concern)
- Speyeria idalia (regal fritillary, state endangered)
Biodiversity Management Considerations
Because restoration of degraded southern wet meadows can be difficult in the absence of favorable hydrology, intact organic soils, and a viable seed source for Carex stricta, conservation efforts should focus on protecting and managing existing southern wet meadows. Maintaining the natural hydrology of southern wet meadow is imperative for the community’s continued existence. This may include avoiding surface water inputs to the meadow from drainage ditches and agricultural fields, and protecting groundwater recharge areas by maintaining native vegetation types in the uplands around the community. Management for southern wet meadows should include the use of prescribed fire to help reduce litter, stimulate seed germination, promote seedling establishment and plant growth, limit shrub and tree encroachment, and control invasive species. Ideally, prescribed fire management of southern wet meadows would be orchestrated with that of surrounding fire-dependent wetland and upland communities. If prescribed burning is not feasible, mowing can be used to reduce woody plant cover but should be restricted to the winter, when ground frost will reduce disturbance to soils, herbaceous plants, and hydrology, or late summer and fall when meadows are dry. Because most wetland shrubs are capable of resprouting when cut (or burned), the application of herbicides to recently cut stumps may be required to maintain open conditions.
Monitoring and control efforts to detect and remove invasive species are critical to the long-term viability of southern wet meadow. Invasive species that threaten the diversity and community structure include purple loosestrife (Lythrum salicaria), reed canary grass (Phalaris arundinacea), reed (Phragmites australis subsp. australis), narrow-leaved cat-tail (Typha angustifolia), hybrid cat-tail (Typha xglauca), glossy buckthorn (Frangula alnus), and multiflora rose (Rosa multiflora).
Community structure and plant diversity can vary significantly among southern wet meadows depending on the dominant species of sedge. Wet meadows dominated by tussock sedge have complex microtopography, which fosters high levels of forb diversity. Wet meadows dominated by lake sedge typically have little microtopographic complexity and low forb diversity.
Similar Natural Communities
- Costello, D.F. 1936. Tussock meadows in southeastern Wisconsin. Botanical Gazette 97: 610-648.
- Curtis, J.T. 1959. The vegetation of Wisconsin. University of Wisconsin Press, Madison, WI. 657 pp.
- Davis, A.M. 1979. Wetland succession, fire and the pollen record: A Midwestern example. American Midland Naturalist 102: 86-94.
- Leach, M.K., and T.J. Givnish. 1996. Ecological determinants of species loss in remnant prairies. Science 273: 1555-1558.
- Kost, M.A. 2004. Natural community abstract for southern wet meadow. Michigan Natural Features Inventory, Lansing, MI. 5 pp.
- Kost, M.A., and D. De Steven. 2000. Plant community responses to prescribed burning in Wisconsin sedge meadows. Natural Areas Journal 20: 36-49.
- Peach, M., and J.B. Zedler. 2006. How tussocks structure sedge meadow vegetation. Wetlands 26(2): 322-335.
- Reuter, D.D. 1986. Sedge meadows of the upper Midwest: A stewardship abstract. Natural Areas Journal 6: 27-34.
- Stout, A.B. 1914. A biological and statistical analysis of the vegetation of a typical wild hay meadow. Transactions of the Wisconsin Academy of Sciences, Arts, and Letters 17: 405-457.
- Warners, D.P. 1993. Species diversity in southern Michigan sedge meadows: Unpublished report to The Nature Conservancy, Michigan Chapter, East Lansing, MI. 35 pp.
- Warners, D.P. 1997. Plant diversity in sedge meadows: Effects of groundwater and fire. Ph.D. dissertation, University of Michigan, Ann Arbor, MI. 231 pp.
For a full list of references used to create this description, please refer to the natural community abstract for southern wet meadow.
Kost, M.A., D.A. Albert, J.G. Cohen, B.S. Slaughter, R.K. Schillo, C.R. Weber, and K.A. Chapman. 2007. Natural Communities of Michigan: Classification and Description. Michigan Natural Features Inventory, Report No. 2007-21, Lansing, MI.