Emergent Marsh

habitat photo
Photo 1 | Photo 2 | Photo 3 | Photo 4 | Photo 5 | Photo 6
Emergent and floating-leaved aquatic macrophytes. Cedarburg Bog State Natural Area, Ozaukee County. Photo by Kate Redmond.

Habitat Description

Habitat Crosswalk

Cowardin: Palustrine or lacustrine; littoral; aquatic bed, rooted vascular and floating; emergent wetland, persistent and nonpersistent (Cowardin et al. 1979).
Shaw and Fredine: Type 3: Inland shallow fresh marsh; Type 4: Inland deep fresh marsh (Shaw and Fredine 1971).
Vegetation of Wisconsin: Emergent aquatic community (Curtis 1971).
Wisconsin Department of Natural Resources Natural Communities: Emergent Marsh (WDNR 2005).
Wisconsin Wetland Inventory: Emergent/wet meadow, persistent and nonpersistent; aquatic bed, submergent and floating (WDNR 1992a).


Emergent marshes support relatively simple but extremely dynamic plant communities compared to most terrestrial habitats. Whether supplied by surface water or ground water, they can experience extreme hydrological variability as a result of climatic conditions, natural disturbance events, or in the case of Great Lakes coastal marshes, adjoining lake water levels and seiche events (Barry et al. 2004). Furthermore, the length of time a wetland retains surface water influences its biological characteristics. Long-term flooding may eliminate many dominant emergent plants while extreme low water levels often expose large areas of mudflats and facilitate the expansion of emergent vegetation (Wilcox et al. 2002, Barry et al. 2004). Extended dry periods or infrequent flooding may reduce aquatic plant diversity within a basin (Mulhouse and Galatowitch 2003). Cowardin et al. (1979) classified water regimes based on water coverage during the growing season, ranging from wetland basins with year-round water coverage (i.e., permanently flooded) to wetland basins with surface water only early in the growing season (i.e., seasonally flooded). The water regimes of impoundments managed for recreation, power generation, or other human uses may be manipulated for extended hydroperiods and minimal hydrologic variation. Because water level manipulations can alter the function and biodiversity of an emergent wetland, it is important to consider their ecological impacts prior to implementation.

Deep and shallow marshes often occur adjacent to one another on a gradient (Thompson and Luthin 2004) and can be identified by plant composition and emergent cover classes. In general, closed stands of emergent vegetation are found in shallower water, open stands in deeper water, and expanses of open water in the deepest part of a wetland (Stewart and Kantrud 1971). Shallow marshes (<15 cm deep) in Wisconsin contain plants such as water sedge, common lake sedge, elliptic spike-rush, soft-stem bulrush, river bulrush, and broad-fruit bur-reed. Non-native plant species such as common reed and purple loosestrife also are common at shallow depths and have the potential to outcompete native plants (see Natural Disturbances and Threats). With increasing water depth, the plant community gradually shifts to hard-stem bulrush, broad-leaved cat-tail, and wild rice as well as floating-leaved species such as American white water-lily, yellow water-lily, water-shield, floating pondweed, and American lotus-lily. A wetland more than one meter deep generally does not support most emergent plant species, but rather transitions into a submergent plant community (see Inland Open Water; Curtis 1971, Hoffman 1990). Bottom substrate and water chemistry also can be critical factors in determining which plants will be successful at a given location (Linde 1969). 

Aquatic vegetation can colonize emergent marshes by seed dispersal, vegetative spread via rhizomes, or germination of a remnant seed bank. When restoring an emergent marsh, the site’s history and landscape position will influence which colonization process prevails (Galatowitsch and van der Valk 1996, Thompson and Luthin 2004). For example, emergent marshes drained with ditches may have more refugial populations of emergent species than tile-drained wetlands, hence more potential for the original plant community to spread and quickly reestablish after a restoration event. Recently drained marshes, especially those drained for less than 20 years, have better colonization potential because of a denser, more diverse seed bank (Galatowitsch and van der Valk 1996). For restored wetlands reliant on dispersal, sites embedded within a wetland complex often require less time to reach plant diversity levels similar to natural wetlands compared to isolated wetlands. In some cases, the degree of isolation may be severe enough to prevent colonization of certain aquatic plant species (Seabloom and van der Valk 2003) and may require deliberate reintroduction techniques. However, the addition of native seeds and propagules alone may not result in a diverse native plant assemblage without the prior removal and subsequent control of invasive species (Mulhouse and Galatowitch 2003).

Historical and Present-day Context and Distribution

Wisconsin’s marsh systems were formed in glacier-scoured basins or in backwater areas of large meandering rivers. Although the historic extent of emergent marsh habitat is unknown, wetlands as a whole covered approximately four million hectares in Wisconsin prior to European settlement. Today, 2.1 million hectares (53%) remain in the state, mostly concentrated in the north (WDNR 2003). The loss and degradation of emergent marshes in Wisconsin is primarily attributed to intensive agriculture, urban development and associated pollution, sedimentation, and exotic species (WDNR 1992b). These activities either directly destroy marsh habitat or negatively alter the ecological condition and function of a marsh. Human activities also have added wetlands to the landscape, sometimes in areas where none previously existed. Large and small impoundments have been developed for human uses such as hydropower, water storage, and recreation (Jahn and Hunt 1964, Wheeler and March 1979). However, extended hydroperiods, reduced hydrological variability, and higher water depths often simplify the ecological communities of these man-made impoundments and reduce their overall wildlife value. Conversely, federal and state programs have developed emergent marshes specifically for wildlife habitat, especially for waterfowl production (WDNR 1995). For example, the Upper Mississippi River/Great Lakes Region Joint Venture has protected, enhanced, or restored more than 37,000 hectares of wetland habitat in Wisconsin.

Natural Disturbances and Threats

Several natural disturbances influence the ecological characteristics of emergent marshes. Natural succession to either an herb-dominated or shrub-dominated wetland community can occur with prolonged drought or other climatic conditions (Rheinhardt and Faser 2001). For example, emergent marsh may succeed to sedge meadow at drier sites, followed by alder thicket or shrub-carr. Invasive plants also may change the plant composition of a site and influence its successional trajectory. Cat-tails are an important component of emergent marsh ecosystems, but a hybrid variety (Typha latifolia x glauca) has dominated many marshes in Wisconsin to the detriment of other wetland flora and associated wildlife (Linde et al. 1976). Although the simplified structure and composition of monotypic cat-tail stands is not suitable for many wetland species, it is important to consider the needs of species that prefer dense cat-tail conditions (e.g., King Rail, Least Bittern) prior to any management activities. Undesirable non-native species such as purple loosestrife, common reed, or reed canary grass are other dominant plants that can potentially alter a marsh community. Common reed in particular can form monospecific colonies along shorelines and shallow water areas and restrict water flow, recreational activities, and aesthetic shoreline views.

Muskrats are dominant wetland herbivores at many emergent marshes and can modify the physical structure of their plant communities. At low densities, muskrats create open water areas in stands of emergent vegetation. At high densities, however, they can denude large areas and create conditions more similar to open water habitat (DeSzalay and Cassidy 2004). Natural and human-induced fires influenced wetlands historically associated with prairie/oak savanna ecosystems by reducing woody encroachment, removing dead herbaceous cover, and exposing the soil to light. Prescribed fire continues as a useful management tool today but may not be appropriate for wetland systems in the northern part of the state or areas lacking a fire history (Thompson and Luthin 2004).

Changing land use remains the most significant threat to emergent marshes and other wetland systems. In urban environments, wetlands continue to be filled for development and roads or degraded by human activities (WDNR 2003). The impervious surfaces (i.e., roofs, driveways, patios) associated with urban areas increases runoff into waterways, which may raise water levels and uproot emergent plants. Storm sewers may drain directly into wetland ecosystems and discharge household chemicals, fertilizers, and other hazardous substances that degrade wetland quality (Thompson and Luthin 2004). In agricultural landscapes, artificially draining fields in preparation for crop production may directly destroy wetlands. Higher nutrient loads from manure, fertilizers, and plant matter can alter the plant and animal community (Thompson and Luthin 2004). Grazing may disturb bottom sediments and create bare areas for invasive species encroachment (Barry et al. 2004). Non-native carp populations also negatively impact emergent marsh communities by disturbing bottom sediments and thus limiting aquatic vegetation and invertebrate production (Kahl 1991).    
Related WBCI Habitats: Inland Open Water, Northern Sedge Meadow and Marsh, Southern Sedge Meadow and Marsh, Wild Rice.

Overall Importance of Habitat for Birds

Emergent marshes are among the most productive of all habitats for waterfowl and other waterbirds (Eldridge 1990). Large marshes or marshes within a wetland complex often support a diverse breeding bird community because of the variety of habitat conditions and nesting substrates. Red-necked Grebe, Least Bittern, Redhead, Ruddy Duck, King Rail, Forster’s Tern, Marsh Wren, and Yellow-headed Blackbird are a few emergent marsh specialists that nest almost exclusively in this habitat type (Hoffman 1990, Robbins 1991). Red-necked Grebe, Redhead, Ruddy Duck, and American Black Duck prefer emergent vegetation interspersed with open water (Eldridge 1990, Stout and Neuchterlein 1999, Steven et al. 2003) whereas King Rail and Marsh Wren typically prefer greater coverage of emergent vegetation (Meanly 1992, Zimmerman et al. 2002). The Yellow-headed Blackbird prefers to nest in deep emergent marsh (Minock and Watson 1983) while Marsh Wren and Forster’s Tern are less particular about water depth (McNicholl et al. 2001). Large emergent marshes also provide important nesting and roosting habitat for area-sensitive species, such as Northern Harrier, American Bittern, and Forster’s Tern (Robbins 1991, Sample and Mossman 1997).

Emergent marshes provide abundant food sources in the form of seeds and invertebrates and provide optimum brood habitat for many of Wisconsin's locally breeding waterfowl. Mudflats associated with edges of emergent marshes support smartweeds, beggarticks, and other plants used by wetland-associated species such as Sora, Common Moorhen, and numerous migrant waterfowl species. Invertebrates abundant in this zone also provide food for most breeding waterfowl as well as breeding American Bittern, Virginia Rail, King Rail, Marsh Wren, and Swamp Sparrow. Migrant shorebirds such as Greater Yellowlegs, Dunlin, Wilson’s Phalarope, and Pectoral Sandpiper also forage along the muddy wetland edge (Robbins 1991, Volkert and Matteson 2001). Slightly deeper water areas adjacent to mudflats are foraging areas for Great Egret, Snowy Egret, and Great Blue Heron. Wild-celery, sago pondweed, bulrush seeds, and other submergent and floating aquatic plants within emergent marshes are consumed by breeding and migrant waterbirds such as Tundra Swan, Trumpeter Swan, Canvasback, Redhead, Ring-necked Duck, and American Coot (Dirschl 1969, Takekawa 1987, Brisban and Mowbray 2002, Woodin and Michot 2002). Considering the diverse habitat requirements of emergent marsh avifauna, it is important to maintain a mosaic of conditions (i.e., composition, structure, and patch size) across the landscape.

Priority Birds

Species Status Habitat and/or Special Habitat Features
Trumpeter Swan B, m Breeds in large marshes with extensive beds of sago pondweed and arrowhead.
Tundra Swan M Migrant in large marshes with extensive beds of sago pondweed and arrowhead.
American Black Duck b, m Prefers open water interspersed with emergent vegetation stands.
Mallard B, M, w Requires adjacent upland habitat for nesting.
Northern Pintail m Prefers open water interspersed with emergent vegetation stands.
Blue-winged Teal B, M Requires adjacent upland habitat and wet prairie for nesting.
Canvasback m Migrant in open marshes with extensive beds of arrowhead and wild-celery.
Redhead B, m Specialist; prefers hemi-marsh with well-interspersed cover and open water areas.
Lesser Scaup m Forages in emergent marshes with >500 m diameter open water zones.
Hooded Merganser f, m  
Red-necked Grebe b Prefers >25% emergent cover interspersed with open water and abundant submergent aquatic vegetation.
American Bittern B, m Nests in emergent marshes >20 ha.
Great Egret f, m Forages in water depths <28 cm.
Snowy Egret f Rare migrant in emergent marshes.
Yellow-crowned Night-Heron f Rare migrant in emergent marshes.
Northern Harrier f, m, w Forages in emergent marshes >40 ha.
King Rail b Specialist; nests in marshes <22 cm deep with dense emergent cover interspersed with shorter, open wet swales (Cooper 2007).
Whooping Crane b Assumed that this species will one day breed and forage in this type.
American Golden-Plover m Found in emergent marshes with exposed mudflats and open aspect.
Greater Yellowlegs M Found in emergent marshes with exposed mudflats.
Solitary Sandpiper M Found in emergent marshes with exposed mudflats.
Whimbrel m Found in emergent marshes with exposed mudflats and open aspect.
Hudsonian Godwit m Found in emergent marshes with exposed mudflats and open aspect.
Marbled Godwit m Found in emergent marshes with exposed mudflats and open aspect.
Dunlin m Found in emergent marshes with exposed mudflats.
Buff-breasted Sandpiper m Found in emergent marshes with exposed mudflats and open aspect.
Short-billed Dowitcher M Found in emergent marshes with exposed mudflats.
Wilson’s Phalarope b, m Requires open, shallow water.
Common Tern b Prefers open water interspersed with emergent vegetation stands.
Forster’s Tern b Nests in large emergent marshes with some areas of open water and muskrat nests.
Black Tern B Specialist; prefers hemi-marsh with well-interspersed cover and open water areas.
Belted Kingfisher f Requires snags or woody perches adjacent to open water areas.
Bank Swallow f Aerial feeding over emergent marshes and open water areas.
Northern Rough-winged Swallow f Aerial feeding over emergent marshes and open water areas.
Barn Swallow f Aerial feeding over emergent marshes and open water areas.
Marsh Wren B Specialist; nests in dense stands of emergent cover, especially with open water patches.
Common Yellowthroat B Prefers tall, rank herbaceous cover.
Swamp Sparrow B Prefers tall, rank herbaceous cover.
Yellow-headed Blackbird b Specialist; nests in emergent vegetation above deep water (>30cm), especially hemi-marsh.


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. Manage for a variety of wetland sizes and habitat conditions (e.g., emergent cover, water level) to support a diverse suite of species and insure brood survival.
  2. Maintain and protect emergent marshes > 40 ha to provide habitat for area-sensitive species like Northern Harrier, Black Tern, Forster’s Tern, and American Bittern (Mossman 1988, Sample and Mossman 1997, Dechant et al. 2001, WDNR 2005).
  3. Create wetland complexes that increase overall wetland connectivity and provide important post-breeding foraging habitat for juvenile rails, herons, bitterns, coots, and moorhens.
  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. In marshes dominated by dense, monotypic stands of nuisance aquatic plants such as hybrid cat-tail, common reed, and reed canary grass, diversify site conditions by using appropriate management techniques such as using a marsh master to create higher and lower elevations and a resultant mosaic of marsh vegetation.
  2. Because site conditions vary, develop property-specific plans for invasive species control and other management actions (see http://www.dnr.wi.gov/org/water/fhp/wetlands/resman.shtml).
  3. Fence out livestock a minimum of 30m from the wetland’s edge to protect nesting birds and water quality (Thompson and Luthin 2004).
  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. Maintain or restore native upland and wetland habitats adjacent to emergent marshes to buffer anthropogenic disturbances, improve colonization of native plants, and provide important nesting habitats (Seabloom and van der Valk 2003, Thompson and Luthin 2004).
  6. Introduce native seeds or propagules to wetland restoration sites lacking remnant seed banks or refugial native plants (Seabloom and van der Valk 2003).
  7. Monitor restored wetlands to assess their progression towards planned objectives and provide feedback for future efforts.
  8. Prior to constructing an impoundment, conduct a complete survey of the site to determine if it is suitable biologically, topographically, and economically (Linde 1969).
  9. Before manipulating water levels in impoundments, determine management objectives:
    • If managing for nesting species, minimize water fluctuations during the breeding season (April-August) and maintain a 50:50 ratio of emergent vegetation interspersed with open water in some units to establish hemi-marsh conditions (Linde 1969).
    • If managing for fall migrants, shallowly flood management units in late June and proceed with slow drawdown from July through October (Helmers 1992).
    • If managing for spring migrants, flood units approximately one month before first heavy frost in fall and maintain conditions through early spring. Draw down slowly from late March to late May. Use vegetative disking where appropriate in fall and early winter to create an invertebrate forage base (Helmers 1992).

Ecological Opportunities

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

Research Needs

  1. Implement a marshbird monitoring program to adequately measure abundance, distribution, population status, and habitat use of key species within emergent marshes.
  2. Assess natural wetland habitat abundance, condition, and trends within and across landscapes to prioritize conservation opportunities.
  3. Inventory flowages and other managed wetlands within the state and assess their role in the sustainability of wetland-associated species.
  4. Evaluate wetland bird response (e.g., productivity, abundance, diversity) to several different management techniques:
    1. Cat-tail control
    2. Mowing
    3. Water level management
    4. Burning
    5. Chemical control of invasive plants
    6. Impacts of landscape-scale management
  5. Conduct comparative studies of reproductive rates at natural and artificial nest structures for Red-necked Grebe, Forster’s Tern, and Black Tern. 
  6. Establish ecological performance measures for wetland restorations and identify the length of time required to completely restore wetland functions and values.


Key Sites

Key Partners

Funding Sources

Information Sources


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