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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) Avena barbata
(2) Bromus hordeaceusPhysiographic features
This site occurs in basins and on alluvial fans below serpentinitic rock. Elevation ranges from 500 to 1,500 feet. Slope ranges from 0 to 9 percent.
Table 2. Representative physiographic features
Landforms (1) Basin floor
(2) Alluvial fan
Elevation 500 – 1500 ft Slope 0 – 9 % Aspect Aspect is not a significant factor Climatic features
Precipitation ranges from 32 to 50 inches per year. The average annual air temperature is 55 F to 59 F. Average annual soil temperature is 55 F to 59 F. The frost-free period is 175 to 250 days.
Table 3 Representative climatic features
Frost-free period (average) 250 days Freeze-free period (average) 0 days Precipitation total (average) 50 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
Soil features
This site is characterized by soils formed from material from serpentinitic rock with a calcium to magnesium ratio of less than 2:1. Typically, they have a clay or clay loam surface 37 inches thick. The substratum to a depth of 60 inches or more is clay with 40 to 55 percent clay, 0 to 12 percent gravel, and slightly effervescent. Some areas may not be effervescent. Effective rooting depth is 60 inches or more. It is neutral to moderately alkaline and slickensides are present throughout the profile. Cracks are open from July to October. Available water capacity is moderate to high and there is a high water table from 42 to 60 inches from December through March. They are somewhat poorly drained and permeability is moderate.
This ecological site is associated with the map units and soil components in the following soil surveys. Future updates to the soil survey(s) may affect these associations.
CA687 156 Maxwell clay, 0-9%Table 4. Representative soil features
Surface texture (1) Clay
Family particle size (1) Clayey
Drainage class Somewhat poorly drained Permeability class Very slow Soil depth 80 – 0 in Available water capacity
(0-40in)5.9 in Soil reaction (1:1 water)
(0-40in)6.6 – 8.4 Ecological dynamics
This list of plants and their relative proportions are based on near normal years. Fluctuations in species composition and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors.
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
Plant Community 1.1Community 1.1
Plant Community 1.1This list of plants and their relative proportions are based on near normal years. Fluctuations in species composition and relative production may change from year to year dependent upon abnormal precipitation or other climatic factors.
The historic climax plant community will produce approximately the following amounts of air-dry vegetation per acre:
Favorable year: 2100 pounds/acre
Normal year: 1500 pounds/acre
Unfavorable year: 800 pounds/acre
Ecological dynamics and major plant community types
The potential for perennial grass dominance on this site has not been determined.
Fire and grazing by native elk and antelope have probably helped to maintain the herbaceous dominance and vigor on this site.
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 720 1350 1890 Forb 80 150 210 Total 800 1500 2100 Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 85–95 Forb2 5–15 Interpretations
Animal community
Recommended stocking rate is 0.2 AUM/ac for an average year (for comparison purposes only). An on-site visit is needed to determine initial stocking rates.
Supporting information
Inventory data references
This data is from an ESD developed for the MLRA 14 Eastern Mendocino Soil Survey, 08/1990 by RLW.
Contributors
RLW
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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