State and transition model
Community 1.1
1.1 Native Perennial Grassland
The historic climax plant community consists predominately of cool and warm season grasses with a small percentage of shrubs and forbs. In the original plant community there is a mixture of both cool and warm season grasses.
1.1 Native Perennial Grassland: The site consist of perennial Native grasses and forbs with minor amounts of shrub cover. Dominant plants species include: James’ galleta, Indian ricegrass, sand dropseed, and western wheat grass.
1.1A:Continuous yearlong herbivory.
Community 1.2
Native Grassland and Shrubland
Palatable cool and warm grasses decreases due to continuous yearlong grazing, thus decreasing the vegetative cover of the native grasses. As the native grasses begin to decline, native shrubs increase their establishment such as fourwing saltbush, broom snakeweed, Greene’s rabbitbrush, rubber rabbitbrush, and whipple cholla. Dominant plant species include: James’ galleta, Indian ricegrass, western wheat grass and fourwing saltbush.
Pathway 1.1a
Community 1.1 to 1.2
Continuous yearlong herbivory.
Pathway 1.2A
Community 1.2 to 1.1
No grazing to rest the rangelands and implement a prescribed grazing plan with favorable precipitation
State 2
2 Native/Invasive Annuals
The general aspect of this state is a native perennial grassland/shrubland with a mix of native and non-native annuals. Invasive annuals have been introduced and are well established in the understory.
Community 2.1
2.1 Native Grasses & Shrubs with Introduced Annuals
If left unmanaged from continuous grazing, undesirable exotic plant species will establish and continue to increase in the understory. ntroduced invasive species most likely to establish themselves when the site deteriorates are prickly Russian thistle, weed Kochia, cheatgrass, filaree and other exotic annuals. There will be a low component of these exotic annuals in the understory, and beginning the process of exotic annuals establishing themselves on site.
Community 2.2
Shrubland with Introduced Annuals
Shrubland with Introduced Annuals
State 3
3 Native/Invasive Tree State
The plant community in this state is dominated by a mix of native and non-native trees and shrubs with scattered patches of grasses and forbs. There is active channel downcutting and deposition.
Community 3.1
Eroded - Native/ Invasive Overstory
As native grasses and shrubs are grazed continuously, the native vegetative cover decreases rapidly and the understory is transformed into an exotic plant community. There will be a higher component of exotic trees, annual grasses and forbs eventually stressing and outcompeting the native plant community. Invasive dominant species include: Tamarisk, Russian olive, broom snakeweed, rubber rabbitbrush, Greene’s rabbitbrush, prickly Russian thistle, common sunflower, weed Kochia, mustards, beeplant, thistles, cheatgrass, foxtail barley, field bindweed, filaree and other exotic annuals. Distribution of these exotics species will be extensive and eventually displace most of the native herbaceous species, as the native species are not given time to reproduce. Bare interspaces with less vegetative cover are visible on the surface resulting in the increased erosion process allowing for more rainfall runoff
Transition T1A
State 1 to 2
Continuous yearlong herbivory/ Unmanaged Rangelands/ Introduction of Exotics
Transition T2A
State 2 to 3
Unmanaged Continuous Grazing/ Severe Prolonged Drought/ Unmanaged Uplands - increased run-on & sediments/ Invasive of Woody Exotics
Restoration pathway R3A
State 3 to 2
Rest/ Prescribe grazing/ Reseeding/ Integrated Shrub &Weed treatment