Montana Natural Heritage Program

Community Field Guide

Scientific Name:
Carex nebrascensis Herbaceous Vegetation

Common Name:
Nebraska sedge Wet Meadow

Community Description

Summary:
These minor wetlands occur on the western Great Plains and throughout much of the western U.S. Elevation ranges from 1000-2800 m (3300-9200 feet). Stands form open meadows that occur along the margins of streambanks, flat floodplains, and lakes often forming a band along the alluvial terrace. Stands have also been sampled from marshy areas surrounding springs and below seeps on lower hillslopes. This association is often found on well-developed soil, but occurs on a wide variety of soil types ranging from saturated organics to Mollisols to Entisols. Soils tend to be fine-textured alluvium, ranging from sandy, silty loam, clay loam, or clay to organic and are typically gleyed and mottled near the surface because of the high water table most of the growing season. The vegetation is characterized by a moderately dense to dense perennial graminoid layer dominated or codominated by Carex nebrascensis (25-99% cover), that generally forms small- to medium-sized meadows. Stands often are nearly pure Carex nebrascensis, but a variety of other graminoid species may be present such as Carex praegracilis, Calamagrostis stricta, Deschampsia caespitosa, Eleocharis palustris, Glyceria striata, Juncus balticus, Schoenoplectus pungens (= Scirpus pungens), or Triglochin maritima. Forb cover is generally low, but can be high in moist locations. Common forbs include Eurybia integrifolia (= Aster integrifolius), Geum macrophyllum, Mentha arvensis, Mimulus glabratus, and Ranunculus cymbalaria. Introduced species Poa pratensis, Poa palustris, and Melilotus officinalis may also be common.

Environment:
This wetland plant association occurs on the western Great Plains and throughout much of the western U.S. Elevation ranges from 1000-2800 m (3300-9200 feet). Stands form open meadows that occur along the margins of streambanks, flat floodplains, and lakes often forming a band along the alluvial terrace. Stands have also been sampled from marshy areas surrounding springs and below seeps on lower hillslopes. This association is often found on well-developed soil, but occurs on a wide variety of soil types ranging from saturated organics to Mollisols to Entisols. Soils tend to be fine-textured alluvium, ranging from sandy, silty loam, clay loam, or clay to organic and are typically gleyed and mottled near the surface because of the high water table most of the growing season.<

>Hansen et al. (1995) identify Carex nebrascensis as a minor type at low to mid-elevations throughout Montana; within southwest Montana and particularly on the Red Rock Lakes National Wildlife Refuge it is also a minor type occurring in small to large patches. Carex nebrascensis in general is found on subirrigated, gently inclined lower slopes, basins and swales, and spans a broad range in hydrologic regimes from semi-permanently flooded to saturated (soils drying to over a meter in depth). Carex nebrascensis generally occupies habitats intermediate (in hydrologic regime) between the wetter associations typically dominated by Carex utriculata or Carex aquatilis and the marginally drier associations Deschampsia caespitosa (=Deschampsia cespitosa), Calamagrostis canadensis or Dasiphora fruticosa ssp. floribunda / Deschampsia caespitosa.

Vegetation:
These wetlands are characterized by a moderately dense to dense perennial graminoid layer dominated or codominated by Carex nebrascensis (25-99% cover), that generally forms small- to medium-sized meadows. Stands often are nearly pure Carex nebrascensis, but a variety of other graminoid species may be present such as Carex praegracilis, Calamagrostis stricta, Deschampsia caespitosa, Eleocharis palustris, Glyceria striata, Juncus balticus, Schoenoplectus pungens (= Scirpus pungens), or Triglochin maritima. Forb cover is generally low, but can be high in moist locations. Common forbs include Eurybia integrifolia (= Aster integrifolius), Geum macrophyllum, Mentha arvensis, Mimulus glabratus, and Ranunculus cymbalaria. Introduced species Poa pratensis, Poa palustris, and Melilotus officinalis may also be common.<

>In Montana, the only shrubs noted in this type are errant specimens of Dasiphora fruticosa ssp. floribunda or Lonicera involucrata. In most southwestern Montana examples of this type the cover of Carex nebrascensis exceeds 60%-70%. Grazing impacted sites tend to have higher cover for Mentha arvensis and Taraxacum officinale.

Range:
This sedge meadow type is widely distributed from the western Great Plains into the western mountains of the United States, ranging from South Dakota and Montana to possibly as far west as Washington, south to California and east to New Mexico.

Dynamics:
In Montana, the Carex nebrascensis community type is considered a grazing-disclimax. Under season-long grazing, Carex nebrascensis increases in abundance, replacing former dominant species (Hansen et al. 1995). However, under extreme grazing conditions and a resulting drop in the water table, Juncus balticus or Poa pratensis can eventually replace Carex nebrascensis. In Nevada, sites dominated by Carex nebrascensis are considered the Potential Natural Community (Manning and Padgett 1995), which appears to be the case in undisturbed stands in Colorado.

Global Rank: G4 State Rank: S4

Global Rank Comments:
This type is widely distributed, but many examples have been heavily grazed by cattle, lowering their floristic quality.

Community References

Identifier:
CEGL001813

Author:
J. Drake, mod. D. Faber-Langendoen, K.A. Schulz and again by S. V. Cooper, MTNHP

Citations:
Baker 1982b, Bourgeron and Engelking 1994, Cooper and Cottrell 1990, Driscoll et al. 1984, Hall 1973, Hall and Hansen 1997, Hansen et al. 1988b, Hansen et al. 1991, Hansen et al. 1995, Jones 1992b, Jones and Walford 1995, Kittel et al. 1994, Kittel et al. 1996, Kittel et al. 1999, Kovalchik 1987, Manning and Padgett 1995, Marriott and Faber-Langendoen 2000, Mutz and Queiroz 1983, Padgett et al. 1988b, Padgett et al. 1989, Steinauer and Rolfsmeier 2000, Youngblood et al. 1985a, Youngblood et al. 1985b

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This information is from the:
Montana Natural Heritage Program
Montana State Library--Natural Resource Information System
1515 East Sixth Ave., Helena, MT 59620-1800 406 444-3989
mtnhp.org
mtnhp@mt.gov