State and transition model
State 1
1 Reference State
The reference state contains plant communities presumed to occur prior to the introduction of non-native plants, livestock grazing, and other modern disturbances. Wyoming big sagebrush dominance depends on time since fire, winter browsing, aroga moth, and/or extended drought. Utah juniper may occur as a minor component of the plant community and is removed by fire prior to maturity.
Community 1.1
1.1 Wyoming Big Sagebrush/Perennial Grass
Production is 25 to 50% grasses 5 to 10% forbs, and 50 to 70% shrubs
Community 1.2
1.2 Perennial Grassland
Production is 50 to 90% grasses, 5 to 15% forbs, and 5 to 35% shrubs.
Community 1.3
1.3 Wyoming Big Sagebrush/Juniper Encroachment
Production is 10 to 25% grasses, 2 to 5% forbs, 65 to 85% shrubs, and 5 to 15% junipers
Pathway 1.1A
Community 1.1 to 1.2
Fire taking out the sagebrush in patches.
Pathway 1.1B
Community 1.1 to 1.3
Encroachment of juniper
Pathway 1.2A
Community 1.2 to 1.1
Time as sagebrush fills in burned areas.
Pathway 1.3B
Community 1.3 to 1.1
A disturbance or treatment to the juniper.
Pathway 1.3A
Community 1.3 to 1.2
Fire burning sagebrush and juniper or mechanical/chemical treatment
State 2
2 Current Potential State
Community 2.1
2.1 Wyoming Big Sagebrush/Perennial Grass
Production is 20 to 50% grasses, 5 to 10% forbs, and 50 to 70% shrubs. Invasive species present but not dominant.
Community 2.2
2.2 Perennial Grassland
Production is 50 to 90% grasses, 5 to 15% forbs, and 5 to 35% shrubs. Invasive species present, but not dominant.
Community 2.3
2.3 Wyoming Big Sagebrush/Juniper Encroachment
Production is 5 to 15% grasses, 2 to 5% forbs, 65 to 85% shrubs, and 5 to 15% Utah juniper. Invasive species present but not dominant.
Pathway 2.1A
Community 2.1 to 2.2
Fire, burning patches of sagebrush.
Pathway 2.1B
Community 2.1 to 2.3
Juniper encroachment
Pathway 2.2A
Community 2.2 to 2.1
Time as sagebrush re-colonizes burned areas.
Pathway 2.3B
Community 2.3 to 2.1
Juniper treatment, drought, or disease.
Pathway 2.3A
Community 2.3 to 2.2
Fire burning large patches of sagebrush and juniper.
State 3
3 Depleted Understory State
Community 3.1
3.1 Wyoming Big Sagebrush/Sparse Understory
Production is 0 to 10% grasses 0 to 5% forbs, 75 to 95% shrubs and 0 to 15% Utah juniper
Community 3.2
3.2 Wyoming Big Sagebrush/Annual Understory
Production is 10 to 30% grasses, 0 to 5% forbs, 60 to 80% shrubs and 0 to 15% Utah juniper.
Pathway 3.1A
Community 3.1 to 3.2
Further degradation and loss of soil with spread of annuals.
Pathway 3.2A
Community 3.2 to 3.1
Stabilizing soil enough to begin colonization of perennial understory plants.
Community 4.1
4.1 Juniper-encroached Shrubland
Production is 0 to 5% grasses, 0 to 5% forbs, 20 to 40% shrubs, and 75 to 95% trees.
Community 4.2
4.2 Juniper Woodland
Production is 0 to 2% grasses, 0 to 5% forbs, 2 to 20% shrubs, and 75 to 95% trees.
Pathway 4.1A
Community 4.1 to 4.2
Extensive coverage of juniper with little understory.
Pathway 4.2A
Community 4.2 to 4.1
Fire or mechanical treatment to set juniper back coupled with colonization of shrubs.
Transition T1A
State 1 to 2
Invasion of introduced species.
Transition T1B
State 1 to 3
Repetitive, high utilization of palatable grass species have increased bare ground and has degraded the site.
Restoration pathway R2A
State 2 to 1
In theory, treatment of introduced species coupled with management to improve soil, water, and plant resources.
Transition T2A
State 2 to 4
Juniper encroachment
Restoration pathway R3A
State 3 to 1
A slow restoration of soil, grass, and hydrologic processes.
Restoration pathway R3B
State 3 to 2
Restoring grass production and cover through careful management.
Transition T3A
State 3 to 4
Juniper encroachment.
Restoration pathway R4A
State 4 to 2
Juniper treatment coupled with effective soil, plant, and hydrology management.
Transition T4A
State 4 to 3
Juniper treatment coupled with accelerated erosion.