Ecological site F005XB107CA

F005XB108CA	Douglas-fir-tanoak/tanoak-California hazelnut, mountain slopes, phyllite and schist, loam and very channery loam F005XB108CA is found adjacent to this site and overlies deeper soils. This site is more productive and has a greater amount of Douglas-fir in the overstory.

F005XB103CA	Douglas-fir-canyon live oak/tanoak, mountain slopes, sandstone and mudstone, very gravelly loam F005XB103CA also occupies shallow soils and has an overstory of canyon live oak and Douglas-fir; however, this site overlies sandstone and mudstone parent material of the Franciscan terrain. Additionally, the current ecological site has a greater cover and diversity of shrub species. F005XB103CA occurs farther west in the Lacks Creek and Redwood Creek drainages.

Tree	(1) Pseudotsuga menziesii (2) Quercus chrysolepis
Shrub	(1) Toxicodendron diversilobum (2) Lithocarpus densiflorus
Herbaceous	(1) Whipplea modesta

Landforms	(1) Mountain slope (2) Ridge
Flooding frequency	None
Ponding frequency	None
Elevation	1000 – 3500 ft
Slope	50 – 110 %
Aspect	SE, S, SW

Frost-free period (average)	250 days
Freeze-free period (average)	250 days
Precipitation total (average)	80 in

Surface texture	(1) Extremely gravelly loam
Family particle size	(1) Loamy
Drainage class	Well drained
Permeability class	Moderately slow
Soil depth	10 – 20 in
Surface fragment cover <=3"	15 – 30 %
Surface fragment cover >3"	10 – 15 %
Available water capacity (0-40in)	1.7 in
Subsurface fragment volume <=3" (Depth not specified)	35 – 70 %
Subsurface fragment volume >3" (Depth not specified)	0 – 10 %

Ecological dynamics

Canyon live oak (Quercus chrysolepis) dominates the driest, steepest slopes. It commonly persists as a subordinate species on these sites when associated with Douglas-fir (Pseudotsuga menziesii) (Burns, 1990, Eyre, 1980). Canyon live oak may regenerate via acorn or through sprouting and will persist in the absence of fire (Termenstein, 1989).

Repeated fire or cutting leads to a dominance of canyon live oak over Douglas-fir on these sites. Conversion to live oak chaparral may occur with repeated burning (Eyre, 1980). With fire exclusion, the area will return to woodland. The fire regime may lead to a mosaic of both species. High severity fire favors the re-sprouting of canyon live oak, and low severity fire will allow for Douglas-fir to be maintained as part of the stand (Jimerson, 1996).

The fire regime is characterized as moderate severity with infrequent fires that are classified as partial stand replacement events (Jimerson, 1994). They may also include areas of low to high severity. Generally because of steep slopes and low stocking levels, the amount of fuels is reduced, thereby lessening fire severity.

State and transition model

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Ecosystem states

1. Reference State - Plant Community 1.1

State 1 submodel, plant communities

1.1. Reference State - Plant Community 1.1

State 1
Reference State - Plant Community 1.1

Community 1.1
Reference State - Plant Community 1.1

gfd

Forest overstory.The overstory is dominated by Douglas-fir with canyon live oak, tanoak, Pacific madrone, and California black oak in the sub-canopy. Overstory average canopy cover: Douglas-fir 10-50% canyon live oak 40-60% tanoak 10-30% Pacific madrone 10-30% California black oak 0-10%

Forest understory. The understory of this site is dominated by shrubs including Pacific poison oak, canyon live oak, and tanoak. Common whipplea can be found throughout this site in moderate amounts with other herbaceous species only found in trace amounts. Understory average canopy cover: Pacific poison oak 5-10% common whipplea 5-10% canyon live oak 5-15% California fescue 0-10% tanoak 0-10% pink honeysuckle 0-5% Douglas-fir 0-5% Pacific madrone 0-5% California hazelnut 0-5% California blackoak 0-5% oceanspray 0-5% Silk tassel 0-2%

Additional community tables

Table 5. Community 1.1 plant community composition

Group	Common name	Symbol	Scientific name	Annual production ()	Foliar cover (%)

Common name	Symbol	Site index low	Site index high	CMAI low	CMAI high	Age of CMAI	Site index curve code	Site index curve basis	Citation
Douglas-fir	PSME	80	110	58	98	–	–	–

Location 1: Humboldt County, CA
Township/Range/Section	T9N R5E S7
UTM zone	N
UTM northing	4557965
UTM easting	445487
General legal description	USGS Quadrangle Weitchpec

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

Number and extent of rills:
Presence of water flow patterns:
Number and height of erosional pedestals or terracettes:
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Number of gullies and erosion associated with gullies:
Extent of wind scoured, blowouts and/or depositional areas:
Amount of litter movement (describe size and distance expected to travel):
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
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:
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Average percent litter cover (%) and depth ( in):
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
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:
Perennial plant reproductive capability:

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Natural ResourcesConservation Service

Ecological site F005XB107CA

Douglas-fir-canyon live oak/Pacific poison oak-tanoak/common whipplea, mountain slopes, phyllite and schist, very gravelly loam

Accessed: 08/06/2026

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Associated sites

Similar sites

Table 1. Dominant plant species

Natural Resources
Conservation Service

Douglas-fir-canyon live oak/Pacific poison oak-tanoak/common whipplea,
mountain slopes,
phyllite and schist, very gravelly loam