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Draft. A draft ecological site description is either incomplete or has not undergone quality control and quality assurance review.
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous (1) Lolium perenne var. multiflorum
(2) Lotus glaberPhysiographic features
This site occurs on tidal marshes and reclaimed tidelands along the margins of San Pablo, San Francisco and Tomales Bays. Slopes range from 0 to 2%, with elevations from -3 to 10 feet above sea level.
Table 2. Representative physiographic features
Landforms (1) Tidal flat
(2) Marsh
Flooding frequency Occasional Elevation -3 – 10 ft Slope 0 – 2 % Water table depth 30 – 60 in Aspect Aspect is not a significant factor Climatic features
Average annual rainfall is 20 to 30 inches. Climatic pattern is typically Mediterranean with most rain falling in winter and spring. There is a direct influence from coastal winds and fog.
Frost-free season is 270 to 300 days. Plant growth occurs throughout the year. However, forage yields may be marginal during the late summer months. Average annual air temperature is 60 to 62 degrees F.
Table 3 Representative climatic features
Frost-free period (average) 300 days Freeze-free period (average) 0 days Precipitation total (average) 30 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
The soil that characterizes this site is very deep, poorly and very poorly drained with a clay surface layer and subsoil texture. The substratum is a silty clay to a silty clay loam. Parent material is a mixed alluvium. Available water capacity is very high, with a soil reaction that is strongly acid to extremely acid. Water table is found at 2.5 to 5 feet. Soil is occasionaly flooded.
Table 4. Representative soil features
Surface texture (1) Clay
Family particle size (1) Clayey
Drainage class Somewhat poorly drained Permeability class Slow Soil depth 80 – 0 in Available water capacity
(0-40in)2.4 in Soil reaction (1:1 water)
(0-40in)3.6 – 6.5 Ecological dynamics
This plant community consists of annual and perennial grasses and forbs. Dominant species are Italian ryegrass (Lolium perenne var. multiflorum), California brome (Bromus carinatus), Narrow-leaf bird's-foot trefoil (Lotus glaber), and curly dock (Rumex spp.).
Other species that can be found include wild oats (Avena spp.), fescues (Festuca spp.), canarygrass (Phalaris spp.), tall fescue (Festuca arundinacea), velvetgrass (Holcus lanatus), vetch (Vicia spp.), mustard (Brassica spp.), thistle (Cirsium spp.), nettleleaf goosefoot (Chenopodium murale), bristly oxtongue (Pichris echioides), and wild radish (Raphanus raphanistrum).
Regression due to mismanaged use by livestock and wildlife results in an increase in less palatable plants such as curly dock, mustard and thistle and a decrease in species such as trefoil, CA brome, and Italian ryegrass. Use by livestock when soils are wet reduces production and increases ponding and runoff.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 2 submodel, plant communities
State 1
Plant Community 1.1Community 1.1
Plant Community 1.1This plant community consists of annual and perennial grasses and forbs. Dominant species are Italian ryegrass (Lolium perenne var. multiflorum), California brome (Bromus carinatus), Narrow-leaf bird's-foot trefoil (Lotus glaber), and curly dock (Rumex spp.).
Other species that can be found include wild oats (Avena spp.), fescues (Festuca spp.), canarygrass (Phalaris spp.), tall fescue (Festuca arundinacea), velvetgrass (Holcus lanatus), vetch (Vicia spp.), mustard (Brassica spp.), thistle (Cirsium spp.), nettleleaf goosefoot (Chenopodium murale), bristly oxtongue (Pichris echioides), and wild radish (Raphanus raphanistrum).
Regression due to mismanaged use by livestock and wildlife results in an increase in less palatable plants such as curly dock, mustard and thistle and a decrease in species such as trefoil, CA brome, and Italian ryegrass. Use by livestock when soils are wet reduces production and increases ponding and runoff.Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 960 1320 1560 Forb 640 880 1040 Total 1600 2200 2600 State 2
Plant Community 2.1Community 2.1
Plant Community 2.1The drained phase of this site is cropped to oat hay. The stubble is grazed, and during abnormally wet years, this site would provide limited grazing due to flooding.
Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Wildlife uses: This site is used by pheasant, quail, deer, dove, raptors, rabbits, songbirds and reptiles. Waterfowl may occasionally graze on this site.
Annual production stocking rates (1980):
Usable forage:
Favorable years - 1380 lbs/ac - 1.3 ac/aum, 4 to 8 ac/au (5 months)*
Normal years - 620 lbs/ac - 0.6 ac/aum, 9 to 18 ac/au (5 months)*
Unfavorable years - 100 lbs/ac - 0.1 ac/aum, 50 to 75 ac/au (5 months)*
*Using 1000 lbs. dry weight forage/aum when forage quality is good (Green feed period).
Hydrological functions
This soil is in hydrologic group D. The runoff curve number in good condition is 81.
Recreational uses
Recreation uses are limited because of occasional flooding and access. Some areas are used for parking (Renaissance Faire) and for hunting clubs. This site provides opportunity for bird watching and other open space aesthetics along tidal areas.
Supporting information
Inventory data references
This data is from the MLRA 14 FOTG from 1980. The type location for the site is: Marin County - 100 feet west of levee, 4400 feet north of Burdell Island on Redwood Sanitary Landfill Property, 122,33,8 W longitude, 38,10,6 N latitude.
Contributors
K.Moseley
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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