Wet Prairie

habitat photo
Photo 1 | Photo 2 | Photo 3
Extensive wet prairie dominated by coarse forbs along the lower Wisconsin River. Avoca Prairie-Savanna State Natural Area, Iowa County. Photo by Eric Epstein.

Habitat Description

Habitat Crosswalk

Cowardin: Palustrine; emergent wetland, persistent (Cowardin et al. 1979).
Sample and Mossman: Wet-mesic or Wet Prairie (Sample and Mossman 1997).
Shaw and Fredine: Type 1: Seasonally flooded basin or flat; Type 2: Inland fresh meadow (Shaw and Fredine 1971).
Vegetation of Wisconsin: Lowland prairie (Curtis 1971).
Wisconsin Department of Natural Resources Natural Communities: Wet Prairie (WDNR 2005).
Wisconsin Wetland Inventory: Emergent/wet meadow, broad- and narrow-leaved persistent (WDNR 1992).

Introduction

Wet Prairie is a tall grass-dominated system with fewer forbs than other prairie types – including wet-mesic prairie - and less than 10% woody cover (Sample and Mossman 1997). Soils are primarily loam or silt loam of neutral pH and have high organic content (Kost et al. 2007). The classification of Wet Prairie, and its distinctiveness from other plant communities, is still under debate (E. Epstein, pers. comm.). Species characteristic of wet prairie include bluejoint grass, prairie cord grass, big blue-stem, upland wild timothy, northern bedstraw, cowbane, yellow-eyed grass, and tall meadow-rue (Curtis 1971, Henderson 1995, WDNR 2005). However, it occurs in lowland areas subjected to frequent inundation and thus shares characteristics of wetland communities. Plants commonly associated with southern sedge meadow, calcareous fen, and even emergent marsh habitats also may occur in wet prairies, including common lake sedge, water sedge, narrow-leaved woolly sedge, black bulrush, and spike-rushes. Despite high soil moisture, some wet prairies contain hummocks or elevated patches of soil that can support plant aggregations associated with mesic prairie types such as smooth aster, prairie dock, stiff goldenrod, and lead-plant (Curtis 1971, Henderson 1995).

Historical and Present-day Context and Distribution

Approximately 42,000 hectares of wet prairie occurred in Wisconsin prior to European settlement, primarily in extinct glacial lake beds, glacial outwash plains, large riverine floodplains, and gently sloping stream valleys south of the tension zone (Curtis 1959 cited in Hoffman and Sample 1988). This grassland type was commonly associated with large wetland complexes containing wet-mesic prairie, southern sedge meadow, calcareous fen, and emergent marsh communities. Wet prairie continues to be associated with these other communities today, especially at large sites. Agriculture, development, and fire suppression have reduced wet prairies to less than 400 hectares (E. Epstein, pers. comm.) and degraded the few remaining parcels. Today, most wet prairies persist as small (<4 ha), highly fragmented remnants in the following ecological landscapes: Southern Lake Michigan Coastal, Central Sand Hills, Western Coulee and Ridges, and Southeast Glacial Plain. Fountain Creek Wet Prairie State Natural Area in Green Lake County is an excellent example of this prairie type (Curtis 1971, Hoffman and Sample 1988, Eggers and Reed 1997, WDNR 2005).

Natural Disturbances and Threats

Presettlement wet prairie was a disturbance-prone, disturbance-dependent system. Periodic fires reduced woody encroachment and helped sustain native prairie vegetation at some sites. Fires created openings for seedling establishment and replenished nutrients to the soil that were essential for plant growth, flowering, and seed set (Kost et al. 2007). High water also may have played an important role in setting back encroaching shrubs and trees. Elk and white-tailed deer may have impacted vegetation at a local level, but it is unclear whether herbivory had significant landscape effects in Wisconsin (TNC 2001). Different disturbance regimes (i.e., disturbance type, scale, frequency, severity, and timing) across the landscape resulted in a complex range of successional stages and a diverse biological community. As native grassland ecosystems were converted to cropland and pasture, however, the landscape mosaic was simplified and the once continuous grassland landscape was fragmented by fields, woodlots, roads, ditches, and other human developments (Steinauer and Collins 1996). These ownership patterns also increased the isolation of the ever-decreasing remnants.

Increased development has severely fragmented native grassland habitats and suppressed, eliminated, or altered the ecological processes necessary to maintain prairie diversity. Approximately 56% of Wisconsin’s native prairie remnants occur on public properties that can be managed for prairie conservation. However, some management tools such as prescribed fire are constrained even on public lands because of public perception and surrounding land use. Without active management, aggressive non-native species such as glossy buckthorn, common reed, reed canary grass, and purple loosestrife invade and simplify the biological community. Most wet prairie remnants are now too scarce, small, and isolated for locally extirpated plant species to recolonize from adjoining or nearby lands. Certain native woody plants such as gray dogwood also can be problematic. Excessive woody cover adversely impacts grassland bird communities by increasing edge effects and providing movement corridors for predators. Hydrological modifications (e.g., ditches, dikes, tiles) and prolonged or intensive grazing also can degrade wet prairie communities by facilitating invasive plant establishment and thereby reducing native plant diversity (Curtis 1971, Hoffman and Sample 1988, Sample and Mossman 1997, WDNR 2005).

Related WBCI Habitats: Southern Sedge Meadow and Marsh, Emergent Marsh, Wet-mesic Prairie.

Overall Importance of Habitat for Birds

Wet Prairie has higher bird diversity than most grassland types because it supports both grassland and wetland bird communities (Hoffman and Sample 1988). The bird community composition of Wet Prairie is similar to other WBCI priority habitats, including Wet-mesic Prairie, Idle Warm Season Grasses and Forbs, Idle Cool Season Grasses and Forbs, and Southern Sedge Meadows. Because most wet prairie sites in Wisconsin contain a shrub component, the bird community also is similar to Shrub-carr and Alder Thicket. Obligate wetland species such as Sora, Wilson’s Snipe, and Marsh Wren may occur where emergent vegetation persists. Tall, dense vegetation provides nesting habitat for priority grassland-obligate species such as Sedge Wren, Bobolink, Henslow’s Sparrow, and Eastern Meadowlark; other more generalist species include Red-winged Blackbird, Common Yellowthroat, and Swamp Sparrow. Mallard and Blue-winged Teal also nest or forage in this prairie type, especially stands contiguous to open water habitats. As shrub cover increases, Bell’s Vireo, Willow Flycatcher, American Goldfinch, Song Sparrow, Yellow Warbler, and other species associated with woody cover may be present. Several grassland-obligate species formerly common in wet prairies are now largely extirpated due to widespread habitat destruction and fragmentation. In particular, area-sensitive species such as Northern Harrier and Greater Prairie-Chicken cannot sustain viable populations on the small, isolated wet prairie patches that remain (Hoffman and Sample 1988, Sample and Mossman 1997, WDNR 2005, Cutright et al. 2006).

Priority Birds

Species Status Habitat and/or Special Habitat Features
Mallard b If appropriate open water for breeding pairs and broods is available nearby.
Blue-winged Teal b If appropriate open water for breeding pairs and broods is available nearby.
Greater Prairie-Chicken b, w Formerly common nesting species but largely extirpated from this type.
Northern Harrier b, m Formerly common nesting species but largely extirpated from this type.
American Golden-Plover m Occasionally occurs in burned areas.
Upland Sandpiper b, m Occurs in prairies embedded in high-grass landscapes with some drier ridges and hummocks.
Marbled Godwit m Occasionally occurs in burned areas.
Barn Owl f Very rare resident in southern and central Wisconsin.
Short-eared Owl b, m, w Formerly common nesting species but largely extirpated from this type.
Willow Flycatcher b, m Requires a shrub component.
Bell’s Vireo b, m Requires a shrub component.
Sedge Wren B, M Prefers dense herbaceous cover dominated by grasses or sedges, and thick litter layer.
Common Yellowthroat B, M Prefers tall, dense herbaceous cover and/or a shrub component.
Clay-colored Sparrow b, m Requires a shrub component.
Henslow’s Sparrow b, m Prefers tall, dense herbaceous cover that is grass-dominated with a substantial component of residual vegetation.
Swamp Sparrow B, M Prefers tall, dense herbaceous cover, especially patches of cat-tail and other coarse emergents.
Dickcissel b, m Occurs at sites with thick-stemmed forbs.
Bobolink B, M  
Eastern Meadowlark b, m  

Objectives

Management Recommendations

Landscape-level Recommendations

  1. Support state and federal programs that manage, enhance, or restore grassland habitats on private lands. Develop cooperative agreements with private landowners to prevent habitat fragmentation and conversion in areas critical for grassland bird conservation.
  2. Develop a digital layer of high-grassland landscapes to focus restoration and conservation efforts. Discourage extensive tree planting within these landscapes to improve the long-term viability of obligate grassland birds.
  3. Partner with the agricultural community to ensure rural working landscapes with high amounts of open space suitable for birds and other wildlife.
  4. Determine what scale of landscape management is possible in an area: medium (400-2,000 hectares) or large (>4,000 hectares). Consider developing a grassland Bird Conservation Area in appropriate landscapes (see Fitzgerald and Pashley 2000).

Site-level Recommendations

  1. Focus management and protection priorities on wet prairie remnants that are large, diverse, support rare species, contain minimal woody cover, and are embedded in landscapes with large amounts of grassland and open habitats (McCoy 2000, DeJong 2001, Bakker et al. 2002).
  2. Develop a digital data layer of wet prairie remnants to better prioritize acquisitions and conservation easements and maximize benefits to grassland birds (Kost et al. 2007).
  3. Restore the upland grassland community bordering a wet prairie site to restrict nutrient and sediment input from surrounding development, improve hydrology, and increase habitat connectivity (Kost et al. 2007).
  4. Restorations aimed at area-sensitive species such as Northern Harrier, Upland Sandpiper, and Henslow’s Sparrow should be at least 50 ha and preferably more than 100 ha in area if the sites are isolated. Sites embedded in high-grassland landscapes can be smaller than this and still provide valuable habitat to these species (Hoffman and Sample 1988, Herkert et al. 1993, Renfrew and Ribic 2008).
  5. Hydrologic restoration will be needed at sites that have been ditched, tiled, or impounded.
  6. Remove linear woody features such as hedgerows and woody fencelines as well as adjacent woodlots to improve site suitability for grassland birds. Low density, scattered shrubs are acceptable and even required by some grassland birds such as Willow Flycatcher and Bell’s Vireo (Sample et al. 2003, WDNR 2005, Kost et al. 2007).
  7. Use prescribed fire in conjunction with cutting and/or herbicides to prevent excessive woody encroachment. Burns scheduled outside the breeding season - either early spring (March-April) or fall (September-November) – are generally best for birds (Sample and Mossman 1997).
  8. Before using prescribed burning for grassland management, determine habitat objectives:
    • If managing for grassland birds with no residual vegetation or woody cover requirement, conduct short (1-2 years) burn rotations.
    • If managing for grassland birds that require a litter or shrub component, conduct longer rotations (>5 years).
    • For large sites, consider only burning portions of the property in a given year to diversify both the vegetation structure and bird community.
    • For remnant prairie sites with significant invasion of invasive cool-season grasses, burn as late as possible in the spring to set back the invasives.
  9. Manage small wet prairie sites for specific subsets of grassland birds rather than maximum species diversity (Vickery et al. 1999).
  10. Develop property-specific plans to control invasive species on prairies, such as common reed, reed canary grass, and glossy buckthorn.
  11. Before grazing grasslands, consider site characteristics and management objectives:
    • If managing a prairie remnant with high native plant diversity, avoid grazing to protect rare plant communities and prevent their conversion to non-native grasses.
    • If managing a remnant prairie site degraded by a significant coverage of invasive shrubs and small trees, consider short-term grazing following mowing to suppress the woody growth. Consult a specialist to develop a grazing plan that benefits wildlife.

Ecological Opportunities

Ecological Landscape Opportunity Management Recommendations
Central Sand Hills Important All
Southeast Glacial Plains Important All
Southern Lake Michigan Coastal Important 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15
Western Coulees and Ridges Important 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15
Central Sand Plains Present 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15
Southwest Savanna Present 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15
Western Prairie Present 1, 2, 3, 6, 7, 9, 10, 11, 12, 13, 14, 15

Research Needs

  1. Identify source and sink grassland habitats and determine habitat, land-use, and landscape features that contribute to differences in bird productivity (Koford and Best 1996, DeJong 2001, Guzy 2005).
  2. Investigate area and landscape requirements for healthy, viable grassland bird populations in addition to studies of species-specific area sensitivities (Sample and Mossman 1997).
  3. Determine the most beneficial arrangement of habitat types within landscapes for grassland birds. Evaluate productivity as well as daily and seasonal habitat use, including the post-fledging period (Guzy 2005).
  4. Determine the maximum threshold for woody vegetation for nesting grassland birds (Guzy 2005).
  5. Investigate adverse impacts of toxic chemicals to grassland birds nesting in or adjacent to agricultural fields (Vickery et al. 1999).
  6. Monitor wet prairie restoration and enhancement activities to assess their wildlife value and adaptively refine management activities.
  7. Collect additional data on vegetative structure and composition to resolve wet prairie classification issues and provide better baseline information on the composition and structure of the community (WDNR 2005).

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.

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