Southern Sedge Meadow and Marsh

habitat photo
Photo 1 | Photo 2 | Photo 3
Southern sedge meadow. White River Marsh Wildlife Area, Green Lake County. Photo by Eric Epstein.

Habitat Description

Habitat Crosswalk

Cowardin: Palustrine; emergent; narrow-leaved persistent (Cowardin et al. 1979).
Shaw and Fredine: Type 2: Inland fresh meadow (Shaw and Fredine 1971).
Vegetation of Wisconsin: Northern and southern sedge meadow (Curtis 1971).
Wisconsin Department of Natural Resources Natural Communities: Southern Sedge Meadow, Calcareous Fen (WDNR 2005).
Wisconsin Wetland Inventory: Narrow-leaved persistent, emergent/wet meadow (WDNR 1992).

Introduction

Southern Sedge Marsh is a wetland community co-dominated by sedges, spike-rushes, bluejoint grass, and emergent vegetation with at least 20% open water and less than 5% woody cover. This habitat frequently establishes when sedge meadows are inundated, either through natural flooding or artificial manipulations of the water table. Southern Sedge Meadow also is dominated by sedges and grasses and contains less than 5% woody cover but has less hydric conditions and fewer open water areas compared to sedge marsh (Sample and Mossman 1997). Sedge meadows in southeastern Wisconsin often occur in complexes with wet prairie, wet-mesic prairie, emergent marsh, calcareous fen, and shrub-carr (WDNR 2005). Although these communities will intergrade, southern sedge meadows are dominated more heavily by sedges than the other types. Hummock-forming upright sedge, lesser panicled sedge, and Sartwell’s sedge (Mossman and Sample 1990, WDNR 2005) are commonly associated with southern sedge meadows as well as bluejoint grass, American water-horehound, Virginia iris, spotted joe-pye-weed, purple-stem aster, and swamp milkweed (Curtis 1971, WDNR 2005). Species that characterize southern but not northern sedge meadows include saw-tooth sunflower, Virginia iris, and Sartwell’s sedge (Curtis 1971, E. Epstein, pers. comm.).

Historical and Present-day Context and Distribution

Historically, sedge meadows covered approximately 459,000 hectares in Wisconsin. Today, approximately 12,000 hectares (3%) remain in moderate to high quality condition (Mossman and Sample 1990). Southern sedge meadows and marshes occur in extinct glacial lake beds, depressions in glacial moraines or pitted outwash, and around lake and stream shorelines (Curtis 1971). They are most prevalent south of the tension zone in the Central Sand Hills and Southeast Glacial Plains Ecological Landscapes and least common in the hilly, unglaciated Driftless Area of southwestern Wisconsin (Mossman and Sample 1990). Small patches of southern sedge meadows and marshes also occur north of the tension zone, particularly within the Northern Lake Michigan Coastal Ecological Landscape (WNDR 2005).

Natural Disturbances and Threats

Sedge meadows and marshes frequently exist in a state of transition and thus are highly sensitive to hydrologic disruption. Natural succession to an herb-dominated or shrub-dominated wetland community can occur with either prolonged drought or flooding. Emergent marsh may replace sedge meadow at sites experiencing extended periods of soil saturation, such as cranberry farms or other publicly-owned water impoundments. Sites with drier conditions may succeed to a wet prairie or support higher shrub densities and succeed to an alder thicket or shrub-carr community. Wildfire may have limited this woody encroachment and maintained historic southern sedge meadow habitats in Wisconsin, particularly where they occurred within a mosaic of prairie and oak savanna. Widespread fire suppression policies enacted in the first half of the twentieth century, especially when they coincided with wetland drainage schemes, likely expedited the conversion of sedge meadow to wet praire (Curtis 1971, E. Epstein, pers. comm.).

Differences in substrate also may contribute to differences in the plant composition and successional sequence of sedge meadows and marshes. Sedimentation caused by urban development, agriculture, and grazing may reduce the microtopography required by native sedge meadow species and facilitate invasive species establishment by creating fresh substrates, nutrients, and canopy gaps. Reed canary grass and cat-tail in particular can form monospecific colonies that simplify the plant composition of southern sedge meadow and marsh communities (Werner and Zedler 2002).

Related WBCI Habitats: Northern Sedge Meadow and Marsh, Wet Prairie, Wet-mesic Prairie, Shrub Carr, Alder Thicket, Emergent Marsh.

Overall Importance of Habitat for Birds

Despite their structural simplicity, sedge meadows and marshes are very important to Wisconsin’s avifauna. Several common breeding species occur statewide in sedge meadow habitats, including Sandhill Crane, Sedge Wren, Common Yellowthroat, Swamp Sparrow, and Red-winged Blackbird (Cutright et al. 2006). The Sedge Wren, a species of high conservation priority, occurs in relatively few other Wisconsin habitats and is most abundant in tall, dense stands with a dense litter layer (Mossman and Sample 1990). Canada Geese use southern sedge meadows extensively in the spring as young sedges are often the first forage available (J. March, pers. comm.). Sedge meadow complexes also are increasingly important to grassland-associated species as the quality and extent of grassland habitats continues to decline. Grassland species such as Savannah Sparrow, Eastern Meadowlark, Ring-necked Pheasant, and Bobolink and area-sensitive grassland species such as Northern Harrier and Short-eared Owl use southern sedge meadows and marshes for foraging, nesting, and roosting. Other bird species associated with southern sedge meadows include Sora, Virginia Rail, Wilson’s Snipe, Wilson’s Phalarope, and Yellow Warbler (Mossman and Sample 1990).

Although some species maintain roughly similar densities in both open and shrubby meadows, other species such as Song Sparrow, American Goldfinch, and Eastern Kingbird increase with the occurrence of woody cover. As shrub encroachment progresses and woody cover increases, more shrub-associated species appear such as Willow Flycatcher, Blue-winged Warbler, and American Woodcock, while suitability decreases for Sedge Wren and many of the grassland-associated birds. An increase in wetness also changes the composition of the bird community. Southern sedge marshes contain wetter, more marsh-like conditions and support higher abundances of certain species compared to sedge meadows. Sedge marshes are more suitable for some open-water species such as Pied-billed Grebe, Wood Duck, Mallard, Blue-winged Teal, Black Tern, Forster’s Tern, and Wilson’s Phalarope. Other species relatively common in southern sedge marshes include American Bittern, Least Bittern, Great Blue Heron, Virginia Rail, Sora, and Yellow-headed Blackbird as well as migratory shorebirds wherever exposed mudflats are present (Mossman and Sample 1990, Cutright et al. 2006).

Priority Birds

Species Status Habitat and/or Special Habitat Features
Canada Goose
(Mississippi Valley Population)		 M  
Trumpeter Swan b Breeds in sedge marshes with abundant submerged aquatic plants.
Mallard B, M Requires adjacent upland habitat for nesting.
Northern Pintail b, m Prefers areas interspersed with emergent vegetation and open water.
Blue-winged Teal B, M Requires adjacent upland habitat for nesting.
Hooded Merganser b, m If nest cavities available nearby.
American Bittern B Found in sedge meadows and marshes >20 ha.
Great Egret f, m Forages in sedge marshes during post-breeding movements.
Snowy Egret m Rare migrant in sedge marshes.
Northern Harrier B, M Found on large sedge meadow/marsh sites.
King Rail b Rare and local breeder in southern Wisconsin.
Whooping Crane b, f Assumed that this species will one day breed and forage in this type.
American Golden-Plover m Found in sedge marshes with exposed mudflats.
Greater Yellowlegs M Found in sedge marshes with exposed mudflats.
Solitary Sandpiper M Found in sedge marshes with exposed mudflats.
Upland Sandpiper m Found in sedge marshes with exposed mudflats.
Whimbrel m Found in sedge marshes with exposed mudflats.
Hudsonian Godwit m Found in sedge marshes with exposed mudflats.
Marbled Godwit m Found in sedge marshes with exposed mudflats.
Buff-breasted Sandpiper m Found in sedge marshes with exposed mudflats.
Short-billed Dowitcher m Found in sedge marshes with exposed mudflats.
Wilson’s Phalarope b, m Requires some standing water and large tracts.
Forster’s Tern b Needs large sedge marshes with thin to moderately thick emergent vegetation.
Black Tern b Needs large sedge marshes with floating nesting substrate.
Barn Owl b, f Rare and local resident in southern and central Wisconsin.
Short-eared Owl b, m, w Occurs as a migrant and/or winters on large tracts
Willow Flycatcher b Requires some shrub cover.
Sedge Wren B Prefers stands of tall, dense vegetation with a dense litter layer.
Common Yellowthroat B Prefers tall, rank herbaceous cover.
Henslow’s Sparrow b Occasionally occurs in mossed bogs.
Swamp Sparrow B Prefers tall, rank herbaceous cover.
Bobolink B Common breeder in large sedge meadow areas.
Eastern Meadowlark b Uncommon breeder in sedge meadows.

Objectives

Stay tuned……. will incorporate habitat acreage objectives from Upper Mississippi River and Great Lakes Region Joint Venture Implementation Plan.

Management Recommendations

Landscape-level Recommendations

  1. Maintain and protect sedge meadow and marsh complexes >40 ha to provide habitat for area-sensitive species like Northern Harrier, Short-eared Owl, and American Bittern (Sample and Mossman 1997, Dechant et al. 2003a, Dechant et al. 2003b).
  2. Identify opportunities to manage sedge meadow and marsh complexes with open upland habitats (prairie, CRP, some savanna) to increase the effective size of openings for area-sensitive species. 
  3. Where applicable, maintain sedge meadows in conjunction with wet prairies, emergent marsh, fens, and other open habitats to protect hydrological function and provide for a diverse suite of species (WDNR 2005).
  4. Maintain wetland function and biodiversity by minimizing impervious surfaces, limiting development, and reducing soil loss and nutrient delivery within watersheds.
  5. Encourage wetland management, protection, and restoration efforts on private lands through existing federal and state programs and by educating private landowners on wetland stewardship.

Site-level Recommendations

  1. Avoid soil disturbance (e.g., pothole creation, heavy grazing, or construction of level ditches) within and adjacent to sedge meadows and marshes to prevent the establishment of invasive plant species (WDNR 2005).
  2. Avoid habitat conversion by properly managing water levels within sedge meadows (i.e., avoid permanent flooding or drainage; Mossman and Sample 1990, WDNR 2005).
  3. Periodically use prescribed fire or other mechanical treatments to prevent woody invasion in sedge meadow habitats (WDNR 2005).
  4. Delay mowing of wetland edges or adjacent upland areas until after the breeding season:
    • For lands managed for conservation, delay mowing until September 1 to protect late-nesting species and fledglings.
    • For lands managed for agricultural production, delay mowing until July 15, or as close to this date as possible, to protect first nest attempts.
    • For lands requiring invasive species control or other priority management actions, weigh the impacts of delayed management versus mowing-induced nest failures. If delayed action threatens the property’s ecological integrity, early mowing may be warranted.
  5.  Because site conditions vary, develop property-specific plans to control invasive species such as reed canary grass and cat-tail (see http://www.dnr.wi.gov/org/water/fhp/wetlands/resman.shtml).

Ecological Opportunities

Ecological Landscape Opportunity Management Recommendations
Central Sand Hills Major All
Southeast Glacial Plains Major All
Central Lake Michigan Coastal Important All
Central Sand Plains Important All
Northern Lake Michigan Coastal Important All
Southern Lake Michigan Coastal Important All
Western Coulee and Ridges Important All
Forest Transition Present All
Southwest Savanna Present All
Western Prairie Present All

Research Needs

  1. Implement a marshbird monitoring program to measure abundance, distribution, population status, and habitat use of key species within southern sedge meadows and marshes.
  2. Assess southern sedge meadow and marsh abundance, condition, and trends within and across landscapes to prioritize conservation opportunities.
  3. Evaluate bird response (e.g., productivity, abundance, diversity) to several different management techniques:
    • Mowing
    • Water level management
    • Burning
    • Chemical control of invasive plants
    • Impacts of landscape-scale management
  4. Monitor sedge meadow and marsh restoration and enhancement activities to assess their wildlife value and adaptively refine management activities.
  5. Assess the potential increased value of southern sedge meadows to grassland-associated birds as upland habitats are converted to corn and other crops for ethanol production. Identify southern sedge meadow management techniques that benefit grassland birds, including reed canary grass control.
  6. Determine the minimum patch size within southern sedge meadows to satisfy the requirements of area-sensitive grassland species such as Northern Harrier, Wilson’s Phalarope, Short-eared Owl, and Bobolink.

Implementation

Key Sites

Key Partners

Funding Sources

Information Sources

References

Contact Information

Kreitinger, K., Y. Steele and A. Paulios, editors. 2013.
The Wisconsin All-bird Conservation Plan, Version 2.0. Wisconsin Bird Conservation Initiative.
Wisconsin Department of Natural Resources. Madison, WI.

Website by J Davis Web Design