Interzonal Cold Semi-wet Fresh Meadow (meadow sedge/tufted hairgrass)

Description

The Reference State is a description of this ecological site just prior to Euro-American settlement but long after the arrival of Native Americans. The description of the Reference State was determined by NRCS Soil Survey Type Site Location information and familiarity with rangeland relict areas where they exist. The pre-settlement climax plant community (1.1) would have been a grassland (meadow) dominated by a rich mixture of native grasses and grass-likes such as meadow sedge (Carex praticola), tufted hairgrass (Deschampsia cespitosa), timothy (Phleum pratense), slender wheatgrass (Elymus trachycaulus), mountain brome (Bromus marginatus), and muttongrass (Poa fendleriana). Minor amounts (less than 15 percent) of forage production was due to native perennial forbs. Mesic shrubs such as silver sagebrush (Artemisia cana ssp. viscidula) and Woods’ rose (Rosa woodsii) were only minor components in the Reference State. A more complete list of species by lifeform for the Reference State is available in accompanying tables in the “Plant Community Composition by Weight and Percentage” section of this document.

Submodel

Description

State 2 is identical to State 1 in form and function, with the exception of the presence of non-native plants and animals, possible extinctions of native species, and a different climate. State 2 is a description of the ecological site shortly following Euro-American settlement. This state can be regarded as the current potential. Grasses and grass-likes would have included meadow sedge, tufted hairgrass, timothy, slender wheatgrass, mountain brome, and muttongrass. These meadows were key in the agricultural development of the lowlands. A very high percentage of these sites were homesteaded and altered by having livestock pasturage, haying, leveling, and irrigation. Native species more tolerant of disturbance (e.g. curlycup gumweed (Grindelia squarrosa), foxtail barley (Hordeum jubatum), Rocky Mountain iris (Iris missouriensis), bull thistle (Cirsium vulgare), sedges (Carex spp.), and timothy increased relative to the less grazing tolerant and palatable grasses and grass-likes such as meadow sedge and tufted hairgrass. Additionally, exotics such as common dandelion (Taraxacum officinale), timothy, Kentucky bluegrass (Poa pratensis), and meadow fescue (Schedonorus pratensis) increased. In general, species richness declined and species equitability became more concentrated in fewer dominants. The single most important impact was whether irrigation took place to supplement the hydrologic input. In the cold temperatures of Rich County, where crop maturation has been a problem (Parson 1996), haying and pasturing have been the more sustainable pattern. Early flooding at the time of peak snowmelt in the watersheds above (May-June) has been the usual pattern.

When a single hay crop is taken in August and the subsequent crop aftermath is grazed by livestock in the fall (T2a), the resulting vegetation becomes dominated by creeping bentgrass (Agrostis stolonifera) and timothy (State 3). If the land use pattern is a single spring flood irrigation followed by heavy growing season livestock grazing (T2b), this results in a sward more dominated by sedges (State 4). If these areas become fenced and heavily grazed season-long (T2c), the more palatable herbs are lost, and mesic shrubs such as silver sagebrush and white sagebrush (Artemisia ludoviciana), and the less palatable grass-likes, especially rushes (Juncus spp.), and forbs such as common dandelion and curlycup gumweed come to prevail (State 5). With subsequent intensified management (e.g. mowing, hay making, fertilization) State 5 can be turned into either State 3 (T5a) or State 4 (T5b). State 4, with deferred grazing during the growing season (T4a), can turn into State 3. Since there are now many exotics present and irrigation systems are unlikely to be dismantled (to restore the original hydrologic regime), a return to the Reference State is not thought possible. Although it would be possible to plow and reseed State 5 with improved exotic forage grasses without subsequent irrigation (T5c), this alternative (State 6) would probably stand up to economic scrutiny or social acceptability for public land.

Submodel

Description

The native grasses creeping bentgrass and timothy are the dominants of this plant community. This plant community is encouraged by fall livestock grazing.

Submodel

Description

Sedges, particularly meadow sedge, will dominate this plant community. This plant community is encouraged by spring flooding (either naturally or by irrigation) followed by heavy growing season livestock grazing. Heavy growing season grazing following flooding encourages the stability of this State. Changes in season of use or levels of use will reduce the stability of this State (i.e. will encourage transition to another State).

Submodel

Description

Mesic shrubs such as silver sagebrush and white sagebrush, and the less palatable grass-likes, especially rushes, and forbs such as common dandelion and curlycup gumweed will dominate this plant community. These plant communities are produced when these areas are fenced and heavily grazed season-long. This stability of this State is maintained by continued season-long utilization of the relatively palatable species, leaving the less palatable species. A reduction of growing season utilization and/or a switch to non-growing season use will reduce the stability of this State (i.e. will encourage transition to another State).

Submodel

Description

Monocultures of exotic grasses such as meadow foxtail, tall oatgrass, colonial bentgrass, bluejoint, or slimstem reedgrass are found at sites where plowing and re-seeding has taken place to improve forage for livestock.

Submodel