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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
Associated sites
R019XD074CA Salt Marsh 14-16" P.Z.
Salt Marsh 13-17" p.z. is a wetter site located on tidal floodplains.
Similar sites
R019XI101CA Sandy dunes 13-34" p.z.
This is a beach and dune ecological site found on the Channel Islands.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) Camissonia cheiranthifolia
(2) Eriogonum parvifoliumPhysiographic features
This site occurs on stabilized coastal sand dunes. Slopes range from 0 to 40 percent on the dunes, but slopes from 0 to 5 percent are more common. Aspects are variable. Elevation ranges from 0 to 85 feet.
Table 2. Representative physiographic features
Landforms (1) Beach plain
(2) Dune
Flooding frequency None Ponding frequency None Elevation 0 – 85 ft Slope 0 – 5 % Aspect Aspect is not a significant factor Climatic features
This site receives slightly less annual rainfall than the more inland sites due to movement of hot and cold air masses and pressure systems influenced by the ocean and surrounding mountains. Roughly 94% of yearly precipitation falls form November through April. The driest months are June, July and August, with those months historically receiving trace amounts of rainfall. The average annual precipitation ranges from 14 to 18 inches. The mean annual air temperature ranges from 60 to 64 degrees F.
There are no reliable climate stations for this specific ecological site. The two stations listed (Oxnard and Los Angeles Civic Center) are on the extreme northwest and southwest of the area.
Table 3 Representative climatic features
Frost-free period (average) 350 days Freeze-free period (average) 0 days Precipitation total (average) 20 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
This site is not influenced by wetland or riparian water features.
Soil features
This ecological site is associated with the Abaft soil series. The Abaft soils are very deep, excessively drained soils that formed in eolian sands from mixed sources. The surface and subsurface texture is loamy sand, with a sand texture from 13 to 59 inches. The Abaft soils are classified as Mixed, thermic Typic Xeropsamments.
This ecological site has been correlated with the following map units and soil components within the Santa Monica Mountain Soil Survey Area (CA692):
Map unit Component Percent
150 Abaft 60
151 Abaft 55Table 4. Representative soil features
Surface texture (1) Loamy sand
Family particle size (1) Sandy
Drainage class Excessively drained Permeability class Rapid Soil depth 60 – 0 in Available water capacity
(0-40in)3.59 – 5.98 in Soil reaction (1:1 water)
(0-40in)6.1 – 7.8 Ecological dynamics
The coastal strand plant community is the interpretive plant community for this ecological site. It is dominated by pink sand verbena (Abronia umbellata), beach suncup (Camissonia cheiranthifolia ssp. suffruticosa), beach-bur (Ambrosia chamissonis), and seacliff buckwheat (Eriogonum parvifolium). This plant community is not extensive within the Santa Monica Mountain National Recreation Area, because the steep bluffs often reach directly to the ocean. Also, development of houses and a highway along the shore have impacted this area. Where this plant community is found several non-native plants have become established. This community has not been able to develop on an extensive dune or beach area, so small pockets are found along the coast. Species composition and cover varies from place to place.
Successional changes are induced by wind and wave deposition and erosion. The barren dunes are actively moving due to direct exposure to wind, and consequently very little grows on them. Along the edge of active dunes, or above the hightide lines, the vegetation begins to slow the movement of sand. This area is often called the beach, or active coastal dune community, which intergrades into the beach foredunes. The primary native dune stabilizers are; sticky sand verbena (Abronia maritima); pink sand verbena (Abronia umbellata); silver beach bur (Ambrosia chamissonis); Sea scale (Atriplex leucophylla); and beach suncup (Camissonia cheiranthifolia ssp. cheiranthifolia). Non-native dune plants include: crystalline iceplant (Mesembryanthemum crystallinum); slender-leaved ice-plant (M. nodiflorum); Sea fig (Carpobrotus chilensis); and scarlet pimpernel (Anagallis arvensis). Several other plant species are also present.
Dune stabilization is often towards the inland side of the dune system, sometimes called backdunes. As vegetation continues to protect the soil from wind and water erosion, it becomes suitable for shrub species that have deeper rooting structures that stabilize and protect the site even better; creating a site that is fully stabilized duneland with very little exposed sand. Salt-tolerant species such as inland saltgrass (Distichlis spicata), Menzies' goldenbush (Isocoma menziesii), and coyotebrush (Baccharis pilularis) are often on the backdunes. Non-native grasses, such as oats (Avena ssp.) and bromes (Bromus spp.) have become established in some areas.
Although the basic pathways of disturbance are know, data is lacking on the plant communities that would exist at different stages. Also this area is fragmented or has restricted access making it difficult to determine what the climax community is or would have been prior to modern impacts.
State and transition model
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textEcosystem states
State 1 submodel, plant communities
State 1
Beach dune communityCommunity 1.1
Beach dune communityThis coastal beach and dune plant community is commonly dominated by pink sand verbena (Abronia umbellata), beach suncup (Camissonia cheiranthifolia ssp. suffruticosa), beach-bur
(Ambrosia chamissonis), and seacliff buckwheat (Eriogonum parvifolium). Other plants that may be present include: giant coreopsis (Coreopsis gigantea), coastal bird's-foot trefoil (Lotus salsuginosus), red sand verbena (Abronia maritima), beach saltbush (Atriplex leucophylla), and saltgrass (Distichlis spicata).
Some common non native plants are, European searocket (Cakile maritima), sea fig (Carpobrotus chilensis), hottentot fig (Carpobrotus edulis), common iceplant (Mesembryanthemum crystallinum), and crimson fountaingrass (Pennisetum setaceum).Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Additional community tables
Table 5. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Forb1 Forbs 130–500 beach suncup CACHS Camissonia cheiranthifolia ssp. suffruticosa 100–360 – pink sand verbena ABUM Abronia umbellata 10–60 – coastal bird's-foot trefoil LOSA Lotus salsuginosus 10–40 – trefoil LOTUS Lotus 10–40 – 3 Non-native Forbs 20–100 European searocket CAMA Cakile maritima 10–60 – lettuce LACTU Lactuca 10–40 – Shrub/Vine2 Sub-shrubs 150–480 silver bur ragweed AMCH4 Ambrosia chamissonis 100–300 – seacliff buckwheat ERPA8 Eriogonum parvifolium 40–120 – giant coreopsis COGI Coreopsis gigantea 10–60 – Grass/Grasslike4 Non-native Grass 10–60 crimson fountaingrass PESE3 Pennisetum setaceum 10–60 – Interpretations
Animal community
The coastal dunes provide nesting sites for snowy plovers (Charadrius alexandrinus nivosus) and least Terns (Sterna antillarum browni). The El Segundo blue butterfly (Euphilotes battoides allyni), a federally endangered species lives in the dunes throughout its lifecycle and feeds exclusively on seacliff buckwheat (Eriogonum parviflorum). Other sea birds use the dunes and beaches for resting, and wading. Harbor seals use undisturbed beaches for haul out sites.
Recreational uses
This ecological site is located near the beach, making these dunes an area often frequented by tourists. However, their lack of overall stability makes them unsuitable for any recreational uses.
Supporting information
Other references
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (2002, February). Fire Effects Information System, [Online]. Available: http://www.fs.fed.us/database/feis/
Contributors
Curtis Talbot, Marchel Munnecke
Rangeland health reference sheet
Interpreting Indicators of Rangeland Health is a qualitative assessment protocol used to determine ecosystem condition based on benchmark characteristics described in the Reference Sheet. A suite of 17 (or more) indicators are typically considered in an assessment. The ecological site(s) representative of an assessment location must be known prior to applying the protocol and must be verified based on soils and climate. Current plant community cannot be used to identify the ecological site.
Author(s)/participant(s) Contact for lead author Date Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
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Number and extent of rills:
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Presence of water flow patterns:
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Number and height of erosional pedestals or terracettes:
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Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
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Number of gullies and erosion associated with gullies:
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Extent of wind scoured, blowouts and/or depositional areas:
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Amount of litter movement (describe size and distance expected to travel):
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Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
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Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
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Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
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Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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Functional/Structural Groups (list in order of descending dominance by above-ground annual-production or live foliar cover using symbols: >>, >, = to indicate much greater than, greater than, and equal to):
Dominant:
Sub-dominant:
Other:
Additional:
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Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
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Average percent litter cover (%) and depth ( in):
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Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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Potential invasive (including noxious) species (native and non-native). List species which BOTH characterize degraded states and have the potential to become a dominant or co-dominant species on the ecological site if their future establishment and growth is not actively controlled by management interventions. Species that become dominant for only one to several years (e.g., short-term response to drought or wildfire) are not invasive plants. Note that unlike other indicators, we are describing what is NOT expected in the reference state for the ecological site:
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Perennial plant reproductive capability:
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