Ecological dynamics

1 Reference State (as represented by active floodplain). Due to active stream dynamics, no one community can describe the reference state and it is common for multiple communities to exist in a relatively small area.
1.1 This plant community is primarily composed of colonizing grasses and sedge and is relatively unstable due to shallow rooted plants and frequent flooding. Willows may exist on site but are typically in small clumps or as single plants
1.1a Site becomes more stable over time, deeper rooted plants increase
1.1b Site experiences flooding that exceeds rooting strength of plant community, heavy grazing reduces shrub component
1.2 This plant community contains a high diversity of willows, dogwood, sedges (beaked, Nebraska, and water), and grasses (tufted hairgrass, American and fowl mannagrass, reedgrass). There are several other grasses and grasslikes (bearded wheatgrass, meadow barley, American sloughgrass, and Baltic rush), along with a variety of forbs. Slight variations in climate and elevation may cause some minor shifting of the willow species. This site is moderately stable and typically can withstand occasional flooding
1.2a Site becomes more stable over time, stream dynamics change (possibly man made structure) causing floodplain to shift to a drier site
1.2b Site experiences catastrophic flooding often associated with extreme weather event and/or ice jam
1.3 Mid-statured trees become more prevalent with interspersed coniferous trees possible. Site is very stable but drying due to natural stream dynamics. Willows remain the primary shrub however buffaloberry, chokecherry, and buffaloberry are increasing. Grasses and sedges remain as the understory.
1.3b Site experiences catastrophic flooding often associated with extreme weather event and/or ice jam
2.1 Mature Tree Dominated state where large cottonwood, spruce, chokecherry, aspen, and birch trees comprise overstory. Grasses often control the understory with dry shrubs. Site is very stable, drying, and has lost nearly all of its stream dynamic (often associated with a down cutting of the stream or loss of stream meandering)
T1a Long term stability created by nearly complete lack of wild flooding (either natural or man created), Improper grazing promotes grass growth.
R2 Site experiences catastrophic flooding often associated with extreme weather events and/or ice jams; Brush management, grazing management will also be necessary
3.1 Wetland characteristics of site altered. Baltic rush and increaser species become prevalent. Site drying due to stream downcutting. Hummocking by livestock possible
T1b Improper grazing (overgrazing or repeated spring grazing), extended drought.
R3 Improved grazing practices (change of season of use, conservative stocking rates), tree/shrub establishment, water impoundments (beaver dams, log jams, or dam analogs)
4.1 Dry riparian site: Site is typically dominated by native grasses such as basin wildrye, thickspike wheatgrass, and slender wheatgrass. Shrubby cinquefoil, buffaloberry, Big sagebrush, and silver sagebrush are dominant shrubs. Site loses hydrology due to downcutting of stream or stream meandering.
T1c Natural stream dynamics creates a dry site that was once wetter. Improper grazing creates accelerated stream downcutting
T3a Drying of system as a result of loss of hydrology and increase in drier shrub species encroaching.
R4 Grazing management (timing and amount to improve shrub and tree establishment), brush management to remove unwanted drier species
5.1 Invaded State: This includes many non-native species that have come to dominate riparian areas. Some species may include: orchard grass, timothy, Kentucky bluegrass, non-native thistles, Russian olive, leafy spurge, spotted knapweed, houndstounge, foxtail barley, whitetop mustard. Often sites are a combination both pasture grasses and invading weeds. Site is often a terminal state; meaning these sites are likely to never return to Reference regardless of management
T1d, T2a, T3b, T4a Sites are invaded by noxious weeds or introduced pasture grasses. Pasture grasses may be planted or a result of invasion from neighboring sites. Improper grazing may be a trigger for invasion however flooding may transport seeds to freshly deposited alluvium.