State 1
Reference

Community 1.1
Shore Pine, Sitka Spruce, California Wax Myrtle, and Evergreen Huckleberry

Structure: Forest with trees, shrubs, and forbs
The reference community is a stabilized dune forest that consists primarily of trees and shrubs. Forbs and grasses commonly are sparse as a result of the dense canopy and salt influence. Mosses and lichens play an important role in this ecosystem by forming a thin, fragile mat on the surface, which helps to stabilize the soil. The most common tree species are Sitka spruce and shore pine, but Douglas-fir (Pseudotsuga menziesii) may be on very old, stabilized dunes. Common shrubs are evergreen huckleberry, salal, coyotebrush, kinnikinnick, California wax myrtle, and western azalea. The herbaceous understory is sparse, but it commonly includes western brackenfern (Pteridium aquilinum), beach lupine (Lupinus littoralis), and beach strawberry (Fragaria chiloensis).
The reference community is influenced by frequent salt spray, and it is subject to wind pruning and windthrow. A large amount of coarse woody debris is common. This site represents a lack of major disturbance and unnatural modifications.

Community 1.2
American Dunegrass and Red Fescue

Structure: Bare ground with scattered grass establishment
Community phase 1.2 represents a forested dune that has been affected by a major disturbance and is at the initiation phase of regeneration. This phase is sparsely vegetated by emerging American dunegrass (Leymus mollis spp. mollis) and red fescue (Festuca rubra). The unstable dune is highly susceptible to wind erosion, trampling, and drought. Minimizing disturbance (natural and unnatural) is important to the vegetative recovery of the site. Monitoring for establishment of non-native species, primarily European beachgrass (Ammophila arenaria), is imperative for a successful native dune plant community.

Community 1.3
Kinnikinnick, Beach Lupine, Coastal Strawberry, American Dunegrass and Red Fescue

Structure: Establishing dune of dwarf shrubs, forbs, and grasses
Community phase 1.3 represents a dune that is quickly stabilizing and has a higher diversity of plant life. Forbs begin to establish as the American dunegrass stabilizes and creates mats. Low-growing ericaceous shrubs such as kinnikinnick may establish during this phase and increase the stability of the dune. Depending on the seed source and condition of the site, shrubs may be entirely absent in some areas. Forbs such as seashore lupine and beach strawberry may be intermixed. Red fescue and seashore bluegrass (Poa macrantha) may be in the grass community.

Community 1.4
Shore Pine, Evergreen Huckleberry, Coyotebrush, and Beach Lupine

Structure: Single story forest with shrubby understory
Community phase 1.4 represents a forested dune that is stabilizing with conifer establishment. Shore pine commonly is the first conifer to establish. Depending on the seed source, Sitka spruce may be dominant in some areas. Shrubs such as evergreen huckleberry, coyotebrush, salal, western azalea, and California wax myrtle will begin to mature. As the canopy cover increases, forbs and grasses will diminish.

Pathway 1.1A
Community 1.1 to 1.2

This pathway represents a major disturbance from a massive tidal surge, an excessively damaging windstorm, wildfire, or extended drought that removes most, if not all, of the existing vegetation.

Pathway 1.2A
Community 1.2 to 1.3

This pathway represents a transition toward dune stabilization from increased plant diversity and cover.

Pathway 1.3A
Community 1.3 to 1.2

This pathway represents a major disturbance from a massive tidal surge, an excessively damaging windstorm, wildfire, or extended drought that removes most, if not all, of the existing vegetation.

Pathway 1.3B
Community 1.3 to 1.4

This pathway represents a transition toward dune stabilization from increased plant diversity and cover.

Pathway 1.4B
Community 1.4 to 1.1

This pathway represents a transition toward dune stabilization from increased plant diversity and cover.

Pathway 1.4A
Community 1.4 to 1.2

This pathway represents a major disturbance from a massive tidal surge, an excessively damaging windstorm, wildfire, or extended drought that removes most, if not all, of the existing vegetation.

State 2
Disturbed

Community 2.1
European Beachgrass and American Beachgrass

Structure: Dune and grassland invaded by non-native plant species
Community phase 2.1 represents an unstable dune that has been entirely disturbed and is susceptible to invasion by non-native species. European beachgrass (Ammophila arenaria) and American beachgrass (Ammophila breviligulata) are exotic grasses that have been used to stabilize dunes. They are highly successful at building thick mats very rapidly. They can tolerate salt spray, wind erosion, and excessive drought. A small remnant community of American dunegrass, seashore lupine, and coastal strawberry may be present. Other common non-native species include little hairgrass (Aira caryophyllea) and hairy cat’s ear (Hypochaeris radicata).

Community 2.2
Shore Pine, Sitka Spruce, Scotch Broom, Common Gorse, European Beachgrass, and American Beachgrass

Structure: Forested dune invaded by non-native species
Community phase 2.2 represents a forested dune that has been susceptible to non-native species. Tree species such as shore pine and Sitka spruce are dominant in the conifer canopy; however, the understory plant community has been significantly altered. Scotch broom (Cytisus scoparius) and common gorse (Ulex europaeus) are exotic shrubs that can spread widely. Depending on specific site dynamics and seed sources, the prevalence of Scotch broom, common gorse, Sitka spruce, and shore pine may be limited to one major shrub and tree species on the site. A small remnant community of evergreen huckleberry, coyotebrush, California wax myrtle, kinnikinnick, and western brackenfern may be present.

Pathway 2.1A
Community 2.1 to 2.2

This pathway represents growth over time with increased establishment of non-native plants.

Pathway 2.2A
Community 2.2 to 2.1

This pathway represents a major disturbance from a massive tidal surge, an excessively damaging windstorm, wildfire, or extended drought that removes most, if not all, of the existing vegetation.

State 3
Developed

This state represents a full departure from the native reference state as a result of human-caused impacts. Off-road vehicle use, residential development, and roadway construction will increase susceptibility to non-native species, restrict sand movement necessary for healthy dunes, and reduce habitat.

Transition T1A
State 1 to 2

This pathway represents a major disturbance from a massive tidal surge, an excessively damaging windstorm, wildfire, or extended drought that removes most, if not all, of the existing vegetation. It also represents a transition from a native plant community to a non-native, invaded plant community. Non-native seed disbursement is introduced (intentionally or unintentionally), which changes the reference community.

Transition T1B
State 1 to 3

This pathway represents human-influenced disturbance from urban sprawl or other development or from excessive use of recreational off-road vehicles. The stabilized dunes and habitat are diminished or completely lost.

Transition T2B
State 2 to 1

This pathway represents restoration of the native plant community. It is extraordinarily difficult to successfully remove established Scotch broom, common gorse, European beachgrass, and American beachgrass. Native seed sources and extensive management and mitigation of brush and non-native species are needed.

Transition T2A
State 2 to 3

This pathway represents human-influenced disturbance from urban sprawl or other development or from excessive use of recreational off-road vehicles. The stabilized dunes and habitat are diminished or completely lost.

Transition T3B
State 3 to 1

This pathway represents restoration of the native plant community and removal of man-made structures. Native seed sources and extensive management and mitigation of brush and non-native species are needed.

Transition T3A
State 3 to 2

This pathway represents removal of man-made structures. Non-native seed disbursement is introduced (intentionally or unintentionally), which changes the reference community.