State 1
State 1 Reference State

State 1 Reference State The reference state contains plant communities presumed to occur on the Alkali Bottom site prior to the introduction of non-native plants, livestock grazing, and other modern disturbances. The reference state is generally dominated by greasewood and deep-rooted perennial bunchgrasses. Greasewood harvests salts from the soil profile and concentrates them in its leaves. As a result, salts are deposited on the soil surface when the leaves are dropped or burned, which increases salinity and pH under greasewood plants. Seepweed commonly establishes in the harsh soils under greasewood plants, while perennial grasses and forbs tend to dominate the spaces between shrubs. Invasive plant species, particularly cheatgrass and Russian thistle, can establish on the site given a seed source and germination sites in disturbed soil. These invasive annuals require little or no disturbance to establish. Once invasive plants establish, return to the reference state may not be possible.

Community 1.1
Community 1.1 Greasewood/Perennial grass: Production is 30-60% perennial grass, 5-15% forbs, and 25-55% shrubs. Non-native species are present but not dominant.

Community 1.1 Greasewood/Perennial grass Phase 1.1 Community phase 1.1 is characterized by a greasewood canopy with diverse perennial grasses and forbs in the interspaces. The fire-return interval for this phase is 35-100 years, which triggers vigorous re-sprouting of greasewood and perennial grasses within one year following fire. Composition by air-dry weight is 40-60% grasses, 5-15% forbs, and 25-50% shrubs. Community 1.1 plant community composition Grass/Grasslike Group Group name Common name Symbol Scientific name Annual production (pounds per acre) Foliar cover (%) 0 Dominant Grasses 200-450 Indian ricegrass ACHY Achnatherum hymenoides 10-120 0-8 needle and thread HECO26 Hesperostipa comata 0-120 0-8 James' galleta PLJA Pleuraphis jamesii 10-100 0-6 alkali sacaton SPAI Sporobolus airoides 0-120 0-8 spike dropseed SPCO4 Sporobolus contractus 0-120 0-8 sand dropseed SPCR Sporobolus cryptandrus 0-120 0-8 mesa dropseed SPFL2 Sporobolus flexuosus 0-120 0-8 1 Sub-Dominant Grasses 50-100 purple threeawn ARPU9 Aristida purpurea 0-20 0-1 blue grama BOGR2 Bouteloua gracilis 0-30 0-2 saltgrass DISP Distichlis spicata 0-10 0-1 squirreltail ELEL5 Elymus elymoides 0-5 0-1 Grass, perennial 2GP Grass, perennial 10-50 1-5 sixweeks fescue VUOC Vulpia octoflora 1-20 0-2 Forb Group Group name Common name Symbol Scientific name Annual production (pounds per acre) Foliar cover (%) 2 Forbs 25-75 snowball sand verbena ABFR2 Abronia fragrans 0-8 0-1 sand gilia ALLE7 Aliciella leptomeria 0-10 0-2 madwort ALYSS Alyssum 0-8 0-6 yellow spiderflower CLLU2 Cleome lutea 0-3 0-1 scrambled eggs COAU2 Corydalis aurea 0-5 0-2 cryptantha CRYPT Cryptantha 3-6 0-2 thicksepal cryptantha CRCR3 Cryptantha crassisepala 0-10 0-3 tansymustard DESCU Descurainia 0-12 0-2 Forb, annual 2FA Forb, annual 5-25 Forb, perennial 2FP Forb, perennial 5-25 gilia GILIA Gilia 0-6 0-1 common pepperweed LEDE Lepidium densiflorum 0-8 0-2 pale evening primrose OEPA Oenothera pallida 0-10 0-1 woolly plantain PLPA2 Plantago patagonica 0-5 0-1 primrose PRIMU Primula 0-10 1-2 ragwort SENEC Senecio 0-5 0-2 longbeak streptanthella STLO4 Streptanthella longirostris 0-2 0-1 Mojave seablite SUMO Suaeda moquinii 0-50 0-5 Townsend daisy TOWNS Townsendia 0-5 0-1

State 2
State 2 Invaded State - Greasewood/perennial grass

State 2 Invaded State The invaded state is similar to the reference state in composition and ecological function, but allows for non-native species to be present. It also includes an at-risk plant community with reduced perennial grass production. When perennial grasses are losing vigor and the ability to propagate themselves, this state is at risk of transitioning to the depleted understory state, which is not capable of recovering perennial grasses without significant management inputs.

Community 2.1
Community 2.1 Greasewood/Perennial Grass: Productionis 30-60% perennial grass, 5-15% forbs, and 25-55% shrubs, Non-native species are present but not dominant.

Community 2.1 Greasewood/Perennial Grass Phase 2.1 Phase 2.1 is similar to the reference plant community in composition and ecological function, but it allows for the presence of non-native/invasive species. It is dominated by greasewood and perennial grasses. Percent composition by air-dry weight is 30-60% perennial grasses, 5-15% forbs, and 25-55% shrubs.

Community 2.2
Community 2.2 At-risk: Greasewood/Reduced perennial grass: Production is 10-25% perennial grass, 5-15% annual non-native species, 5-15% forbs, and 50-65% shrubs. non-native species co-dominate the understory with perennial grass.

Community 2.2 At-risk: Greasewood/Reduced perennial grass Phase 2.2 This plant community is at-risk of crossing a threshold into the depleted understory state (state 3). Years of excessive grazing of perennial grasses during growth has favored non-native invasive species, primarily cheatgrass and/or Russian thistle, to co-dominate the understory. Prescribed grazing is required to improve the reproductive capability of perennial grasses and avoid the transition to state 3.

Pathway P2.1
Community 2.1 to 2.2

Repetitive, high utilization of palatable grass species have given shrubs a competitive advantage.

Pathway P2.2
Community 2.2 to 2.1

Management to improve palatable grass species, along with a set back to the shrubs such as fire.

State 3
State 3 Depleted Understory State

State 3 Depleted Understory State The depleted understory state occurs when perennial grasses have been lost from the understory. Perennial forbs may also be reduced. Interspaces may be sparsely vegetated or dominated by Russian thistle or other annual invasive species. This state is not as capable of carrying fire due to a reduction in fine fuels. As a result, greasewood may continue to increase as the understory continues to be reduced.

Community 3.1
Community 3.1 Greasewood/Limited understory: Production is 5-15% annual grasses and forbs, and 85-95% shrubs. Non-native species dominate the sparse understory.

Community 3.1 Greasewood/Limited understory Phase 3.1 3.1 after tamarisk removal Phase 3.1 is characterized by greasewood dominance and a sparse understory that results from continued overgrazing. Increased size and production of greasewood plants may result in increased soil salinity in surface layers, further reinforcing greaswood dominance on the site.

Community 3.2
Community 3.2 Greasewood/Annual understory: Production is 15-35% annual grasses and forbs, and 65-85% shrubs. non-native species dominate the understory.

Community 3.2 Greasewood/Annual understory Phase 3.2 This phase is dominated by greasewood in the overstory and annual grasses and/or forbs in the understory. Pathway 3.2a Community 3.2 to 3.1 Greasewood/Annual understory Greasewood/Limited understory This pathway occurs when livestock use reduces the annual invasive species between shrubs. It may also be reinforced by an increase in salt deposits on the soil surface from increased greasewood production.

Community 3.3

Pathway 3.1a
Community 3.1 to 3.2

Further degredation to the understory reducing annual production to annuals.

Pathway 3.1b
Community 3.2 to 3.1

This pathway occurs when livestock use reduces the annual invasive species between shrubs. It may also be reinforced by an increase in salt deposits on the soil surface from increased greasewood production.

State 4
State 4 Tamarisk State - Tamarisk - Greasewood

State 4 Tamarisk State This state primarily occurs on low stream terraces. The stream provides a corridor for tamarisk invasion, which spreads throughout the alkali bottom on low stream terraces, eventually dominating the site.

Community 4.1
Community 4.1 Greasewood-Tamarisk: Production is 0-15% perennial and/or annual grasses, 10-40% forbs, 50-95% tamarisk, and 0-20% shrubs

Community 4.1 Greasewood-Tamarisk Phase 4.1 This community phase is characterized by the establishment and persistence of tamarisk. Greasewood is co-dominant with tamarisk in this phase.

Community 4.2
Community 4.2 Tamarisk Dominated: production is 0-5% perennial and/or annual grasses, 10-40% forbs, 50-90% tamarisk, and 0-20% shrubs.

Community 4.2 Tamarisk Dominated Phase 4.2 This community phase is characterized by dominance of tamarisk. Greasewood is not dominant in this phase, but may be present as a sub-dominant shrub. Invasive grasses and forbs are often present in this phase.

Pathway 4.1a
Community 4.1 to 4.2

Pathway 4.1b
Community 4.2 to 4.1

Transition T1A
State 1 to 2

A decline of ecosystem health along with invasion of introduced species. Once introduced species have invaded it is unlikely the site can be restored to reference.

Transition T2a
State 2 to 3

Repetitive, high utilization of palatable understory species over time increases bare ground and erosion.

Transition T2b
State 2 to 4

Site degredation along with invasion of tamarisk and an increase in greasewood.

Transition T3
State 3 to 4

Further degredation along with establishment of tamarisk.

Restoration pathway R4
State 4 to 3

Treatment to reduced tamarisk along with further colonization of shrubs.