Northern Prairie Wildlife Research Center
Native grasslands (Fig. 5) on the WSA constitute typical xeric mixed-grass prairie. Because of the hummocky topography, most of the vegetation of similar nature is either in patches, clones, or thickets. The largest tracts of any one plant community are usually on uniform soil zones with little slope. Complex vegetation zonation occurs throughout the study area and several different communities may be present along one slope with only slight changes in soils, topography, moisture, or drainage regimes. The most obvious vegetative zonation occurs between brush clumps or thickets, marshes, and grass-forb associations. One prevalent zone is around the edges of wolfberry (Symphoricarpos occidentalis) thickets (Fig. 5). Other common shrubs on the area are silverberry (Elaeagnus comutata), prairie wild rose (Rosa arkansana), thornapple (Crataegus chrysocarpa), chokecherry (Prunus virginiana), Juneberry (Amelanchler alnifolia), wild black currant (Ribes americanum), and willow (Salix spp.).
The only trees common to the area are cottonwoods (Populus deltoides). Occasionally, single trees of green ash (Fraxinus pennsylvanica), hackberry (Celtis occidentalis), or Siberian elm (Ulmus pumila) occur on prairie sites. The only other trees are those planted in tree groves or shelterbelts.
Dix and Smeins (1967) recognized relative positions of vegetational units by topographic relief or landscape within the transitional mixed-grass prairie belt in North Dakota. Uplands were divided into high prairie, mid-prairie, and low prairie, and lowlands into meadow and marsh. Because Woodworth lies within this same vegetational belt, we have used their terminology to describe the aspect of prairie on the study area (Fig. 6).
High prairie grassland sites are usually on excessively drained Sioux, Fordville, or Buse soils that are shallow, gravelly regosols. Brush species, except for Rosa, are nearly always absent. Grass stands are usually dominated by various combinations of blue grama (Bouteloua gracilis), needle and thread (Stipa comata), fringed sage (Artemisia frigida), narrow-leaved blazing star (Liatris punctata), prairie wild rose, hairy golden aster (Chrysopsis villosa), pasque-flower (Anemone patens), threadleaved sedge (Carex filifolia), and Missouri goldenrod (Solidago missouriensis).
Mid-prairie grassland sites are usually on level to slightly or moderately sloping terrain with Barnes soils that are well drained chernozems. Stands on these sites are dominated by various combinations of green needlegrass (Stipa viridula), Kentucky bluegrass (Poa pratensis), needle and thread, western wheatgrass (Agropyron smithii), wolfberry, northern bedstraw (Galium boreale), chickweed (Cerastium arvense), white sage (Artemisia ludoviciana), yellow sedge (Carex pennsylvanica), stiff sunflower (Helianthus rigidus), and silver-leaf scurf pea (Psoralea argophylla). The mid-prairie sites are vegetationally the most complex communities on the area.
Low prairie grassland sites are on moderately drained chernozem soils. Dominant species include big bluestem (Andropogon gerardi), little bluestem (A. scoparius), Baltic rush (Juncus balticus), cordgrass (Spartina pectinata), switchgrass (Panicum virgatum), blackeyed Susan (Rudbeckla hirsuta), and Maximilian's sunflower (Helianthus maximiliani). Less dominant species of these sites are smooth aster (Aster simplex), prairie dropseed (Sporobolus heterolepis), wild licorice (Glycyrrhiza lepidota), and Canada anemone (Anemone canadensis).
Lowland meadow grassland sites are poorly drained and the water table is usually within the rooting depths of most plants. Gravitational water is usually present in the marsh sites, and in these depressions or potholes, soils are usually inundated for extended periods. Detailed descriptions of the vegetation of meadow and marsh sites have been reported by Stewart and Kantrud (1969, 1971); only the major dominants are presented here. These sites are usually on Colvin, Parnell, or Tetonka soils.
Dominant species of meadows on the area are northern reedgrass (Calamagrostis inexpansa), narrow-leafed sedge (Carex lanuginosa), foxtail barley (Hordeum jubatum), cordgrass, Baltic rush, smooth aster, wild mint (Mentha arvensis), fowl bluegrass (Poa palustris), and hedge nettle (Stachys palustris).
Dominant species of the marshes at the WSA are slough sedge (Carex atherodes), whitetop (Scolochloa festucacea), common cattail (Typha latifolia), hybrid cattail (T. glauca), hardstem bulrush (Scirpus acutus), slender bulrush (S. heterochaetus), softstem bulrush (S. validus), spikerush (Eleocharis palustris), common smartweed (Polygonum coccineum), sloughgrass (Beckmannia syzigachne), water-plantain (Alisma triviale), bur-reed (Sparganium eurycarpum), water parsnip (Sium suave), and tall mannagrass (Glyceria grandis).