Natural Resources
Conservation Service
Ecological site F005XB104CA
Jeffery pine/huckleberry oak,
mountain slopes,
serpentinite and peridotite, clay loam
Accessed: 08/17/2026
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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
F005XB105CA Douglas-fir-tanoak/huckleberry oak, mountain slopes, serpentinite and peridotite, clay loam
F005XB105CA id often found in conjunction with this site.
Table 1. Dominant plant species
Tree (1) Pinus jeffreyi
Shrub (1) Quercus vacciniifolia
Herbaceous Not specified
Physiographic features
This ecological site is found on the eastern margins of Mill and Rock creeks. It occurs on upper mountain slopes and ridges, which are strongly sloping to very steep.
Table 2. Representative physiographic features
Landforms (1) Mountain slope
(2) Ridge
Flooding frequency None Ponding frequency None Elevation 180 – 3012 ft Slope 9 – 75 % Water table depth 60 – 0 in Aspect Aspect is not a significant factor Climatic features
The climate on this site is characterized by cold winters and hot, dry summers. Mean annual temperature is 50 to 55 degrees F. The average annual precipitation ranges from 90 to 120 inches with most falling as rain from November to April.
Table 3 Representative climatic features
Frost-free period (average) 180 days Freeze-free period (average) 0 days Precipitation total (average) 120 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
There are no influencing hydrological features on the site.
Soil features
These well-drained, very deep soils developed from colluvium and residuum derived from serpentinite, peridotite, and serpentinized peridotite of the Klamath terrain. They are neutral to moderately acidic at 40 inches with a dominantly loamy subsurface rock content ranging from very gravelly to extremely gravelly.
Soils correlated to this ecological site include the following:
Map unit Soil
759 Walnett
760 Walnett
Table 4. Representative soil features
Surface texture (1) Very stony loam
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately slow to slow Soil depth 60 – 0 in Surface fragment cover <=3" Not specified Surface fragment cover >3" 10 – 30 % Available water capacity
(0-40in)2 – 6 in Calcium carbonate equivalent
(0-40in)Not specified Electrical conductivity
(0-40in)Not specified Sodium adsorption ratio
(0-40in)Not specified Soil reaction (1:1 water)
(0-40in)5.6 – 6.6 Subsurface fragment volume <=3"
(Depth not specified)30 – 75 % Subsurface fragment volume >3"
(Depth not specified)5 – 13 % Ecological dynamics
Serpentine environments are largely influenced by the chemical composition of the underlying parent material. High amounts of magnesium and iron, coupled with low amounts of calcium, low nutrient availability, and other related environmental factors create distinct plant communities (Kruckberg, 1984). Plant growth and productivity are often limited by high heat and low water availability on these sites (Jimerson, 1994).
Natural disturbances in the serpentine zone are fire and to some degree, insects and disease (Jimerson et al, 1995). The area is characterized as having a mixed fire regime, with both low and high intensity fires creating a mosaic of plant communities that are diverse in species composition and structure (Arno and Bunnell, 2002).
Fire history in the Klamath-Siskiyou region has not been widely researched (Frost and Sweeny, 2000). The open nature of the canopy and the discontinuity in ground cover, leads many to believe that the areas were grassier, and that historical fires were of low intensity. A few fires may be stand-replacing, especially in the drier, higher elevation sites with more huckleberry oak (Quercus vacciniifolia) shrub cover. Fire plays an integral role in species composition and structure on serpentine sites and the effects of fire on individual species needs more investigation and monitoring (Parker, 1990).
Following a stand-replacing fire, knobcone pine (Pinus attenuate) will often establish in a site, if a seed source is present; it may dominate early seral stages (Jimerson, et al, 1995). Knobcone pine has a closed cone habit (serotinous cones) and is dependent on periodic stand-replacing fires for seed dispersal. In the absence of fire, knobcone stands will senesce and eventually conifers or shrubs will infill (Howard, 1992). Jeffrey pine (Pinus jeffreyi) is moderately resistant to fire; its thick bark and bud scales protect the tree from fire damage (Wagener, 1961).
With fire exclusion, Douglas-fir will infill under the shade of Jeffrey pine, especially when soil moisture conditions are adequate. In isolated moist areas or in drainages of the site, Port Orford cedar (Chamaecyparis lawsoniana) may be a stand component that will infill under Douglas-fir (This small but important plant community is not described in the State and Transition model at the mapping level of the soil survey. See the references in the Supporting Information Section for sources on serpentine plant associations).
Western dwarf mistletoe (Arceuthobium campylopodum) is a very common pathogen found on Jeffrey pine. It forms brooms in twigs and infected branches and severe infections can result in decreased tree growth and death of the host. Weakened trees are often susceptible to insect attacks by bark beetles (Burns and Honekala, 1990).
State and transition model
Custom diagramStandard diagram
Figure 3. Jeffery pine/huckleberry oak model
More interactive model formats are also available. View Interactive Models
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 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 6 submodel, plant communities
State 1
Jeffrey pine/huckleberry oakCommunity 1.1
Jeffrey pine/huckleberry oakPlant Community 1. The interpretive plant community is also the historic climax plant community (HCPC). The site is open with old-growth Jeffrey pine (Pinus jeffreyi). Douglas-fir (Pseudotsuga menziesii) can be found in draws where moisture and soil conditions are favorable. There is a sparse understory shrub cover of huckleberry oak (Quercus vacciniifolia), California buckthorn (Frangula californica) (also known as California coffeeberry), oceanspray (Holodiscus), and pinemat manzanita (Arctostaphylos nevadensis). Other shrubs that may be found include creeping juniper (Juniperus horizontalis) and dwarf ceanothus (Ceanothus pumilus). Perennial grasses are primarily Idaho fescue (Festuca idahoensis) with a minor amount of California fescue (Festuca californica). Herbaceous species include common yarrow (Achillea spp.).*
1a) In the event of a severe canopy fire, or a block harvest followed by prescribed burning, the plant community could be temporarily set back to shrubs and grasses. Huckleberry oak and California buckthorn may be top-killed by fire but will re-sprout from the root crown (Howard, 1992), McMurray, 1990). Oceanspray may re-sprout from the root crown or from seeds stored in the soil (Archer, 2000). See PC#2.
1b) If fire is excluded, Douglas-fir may encroach into the plant community causing a shift to PC#6.
1c) Periodic low intensity fires would tend to maintain this plant community and allow for a natural regeneration of Jeffrey pine.
1d) In the event of a stand-replacement fire, a mixed stand of knobcone and Jeffrey pine could be established. See PC#4.
1e) With fire exclusion, Douglas-fir may infill under the shade of Jeffrey pine. See PC#5.
* The serpentine plant community is extremely diverse and complex. This ecological site description has been generalized to reflect the Soil Order Level 3 mapping that took place. For more detailed plant association descriptions, see "A Field Guide to Serpentine Plant Associations and Sensitive Plants in North Western California", US Forest Service publication R5-ECOL-TP-006, 1995.
Figure 4. Annual production by plant type (representative values) or group (midpoint values)
State 2
Manzanita spp./California buckthorn/huckleberry oak/Fescue spp.Community 2.1
Manzanita spp./California buckthorn/huckleberry oak/Fescue spp.Plant Community 2. A mixed shrub and grass understory is created following a severe fire or harvesting. Various manzanita species, huckleberry oak, California buckthorn, and oceanspray will re-sprout from the root crown or reproduce via acorns or seeds. An increase in shrub distribution is expected following severe disturbances. These harsh sites may be dominated by shrubs or bare ground for long periods following wildfire or harvesting (Jimerson, 1995).
2a) knobcone pine may infill into the area following a moderate to severe fire if a seed source is present. See PC#4.
2b) Jeffrey pine from adjacent unburned areas will begin to infill. If some trees are not completely killed, a "stress crop" of seeds will be released which may create significant Jeffrey pine regeneration.
2c) This plant community could potentially be maintained through periodic burning.
State 3
Huckleberry oak/manzanita spp/California buckthorn/Jeffrey pineCommunity 3.1
Huckleberry oak/manzanita spp/California buckthorn/Jeffrey pinePlant Community 3. The plant community is characterized by shrubs, including huckleberry oak, manzanita spp., and California buckthorn. Though a shrub community has become more dominant, Jeffrey pine is able to establish in the gaps of the shrub layer.
3a) With fire exclusion, there is the potential for Douglas-fir to become established in the shade of the Jeffrey pine, especially if soils are deep. Pinemat manzanita and huckleberry oak may invade (Jimerson, 1994). See PC#5.
3b) In the event of a stand-replacing fire, knobcone and Jeffrey pine stands may form a dense thicket. There will also be an increase in sprouting shrubs such California buckthorn, huckleberry oak and pinemat manzanita. See PC# 4.
State 4
Knobcone pine/huckleberry oak/pinemat manzanitaCommunity 4.1
Knobcone pine/huckleberry oak/pinemat manzanitaPlant Community 4. The plant community is dominated by an even-aged stand of knobcone pine, with a minor component of Jeffrey pine. The shrub layer is dominated by huckleberry oak, pinemat manzanita, and lesser amounts of California buckthorn. Some whiteleaf manzanita (Arctostaphylos manzanita) may be found as well. Small areas of the perennial grasses Idaho and California fescue will remain interspersed within the brush and trees.
4a) In the absence of fire, knobcone stands will senesce after approximately 60 to 80 years and conifers or shrubs will gradually infill (Howard, 1992). Seeds from adjacent stands of Douglas-fir may establish. See PC#5.
4b) Moderate to severe fire could maintain a knobcone pine-dominated community with a brush understory.
4c) Repeated periodic fire could favor Jeffrey pine and reduce or eliminate knobcone pine. See PC#1.
State 5
Jeffrey pine/Douglas-fir/huckleberry oak/California buckthorn/pinemat manzanitaCommunity 5.1
Jeffrey pine/Douglas-fir/huckleberry oak/California buckthorn/pinemat manzanitaPlant Community 5. Continued fire exclusion allows for a change in species compositions. Where soil conditions are favorable, the stand may increase in the composition of Douglas-fir. The overstory is now a mixed Jeffrey pine/Douglas-fir stand with a shrub-dominated understory of whiteleaf manzanita and huckleberry oak. Small areas of Idaho and California fescues remain.
5a) With continued fire exclusion, and where soil conditions are favorable, Douglas-fir continues to infill. Jeffrey pine can no longer regenerate in the understory due to surface litter buildup and increased competition from shrubs. See PC#6.
5b) A severe stand-replacing fire could allow the pioneering knobcone pine plant community to become re-established. See PC#4.
State 6
Douglas-fir/huckleberry oak/manzanita sppCommunity 6.1
Douglas-fir/huckleberry oak/manzanita sppPlant Community 6. The plant community is created as a result of fire exclusion. Douglas fir dominates the overstory, with some knobcone or Jeffrey pine in minor amounts. The understory is dominated by huckleberry oak and manzanita species, including pinemat and sticky whiteleaf; Pacific rhododendron (Rhododendron macrophyllum), red huckleberry (Vaccinium parvifolium) and California buckthorn are also found.
Additional community tables
Table 5. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Shrub/Vine1 200–400 Table 6. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 7. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 8. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 9. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 6.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Studies are lacking with regard to the animal communities within serpentine environments. Kruckeburg briefly discusses three papers that deal with animals found in serpentine environments, including butterflies, pocket gophers and populations of salamanders (Kruckeburg, 1984).
Hydrological functions
These soils are well-drained. They are highly erosive (Kruckeburg, 1992) and easily degraded.
Hydrologic group--C.Recreational uses
Recreational use and development may be limited by steep slopes and the high amount of rock fragments found in the soils.
Wood products
Jeffrey pine grows very slowly on serpentine soils and is generally of poor quality for wood products. Site productivity is generally low on these sites, and the erosive nature of the soils does not make them well suited for timber management.
Other products
Native Americans gathered plant materials for cultural purposes and likely hunted in these areas.
Other information
Jeffrey pine has been utilized for the rehabilitation of disturbed sites in northeastern California (Butterfield, 1980).
Serpentine sites provide habitats for small mammals and birds and contain a diversity of rare and sensitive plant species.
Supporting information
Inventory data references
Data was collected at the following forest soil pits: 759 Walnett 04-109, 04-108, 04-110, 04-117, 04-118 760 Walnett 04-115
Type locality
Location 1: Del Norte County, CA Location 2: Humboldt County, CA Township/Range/Section T16N R1E S36 UTM zone N UTM northing 4620909 UTM easting 416204 General legal description USGS Quadrangle Childshill Other references
Arno, S. F and S. Allison-Bunnell, 2002. Flames in Our Forest, Disaster or renewal? Island Press.
Burns, Russell M., and Barbara H. Honkala, tech coords. 1990. Silvics of North America: 1. Conifers. Aricultural Handbook 654. U.S. Department of Agriculture, Forest Service, Washington, DC. vol. 1, 675 p.
Haybeck, R. J. 1992. Pinus jeffreyi. In: FIre Effects Information System, [Online]. Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Avaialble: http://www.fs.fed.us/database/feis/ [2006, April 24].
Kruckberg, Authur R., 1984. California Serpentines: Flora, Vegetation, Geology, Soils, and Management Problems. University of California Press.
Howard, Janet L., 1992. Pinus attenuata. In: Fire Effects Information System, [Online], U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer) Available: http://www.fs.fed.us/database/ [2006, April 24]
Jimerson, T.M., et al. 1995 A Field Guide to Serpentine Plant Associations And Sensitive Plants in Northwestern California. U.S. Department of Agriculture, Forest Service, Pacific Southwest Region. R5-ECOL-TP-006.
Parker, V.T., 1990. Problems encountered while mimicking nature in vegetation management; an example from fire-prone vegetation. In: Proceedings of the 15th Annual Natural Areas Conference, Ecosystem Management; Rare Species and Significant Habitats. R.S. Mitchell, C.J. Sheviak and D.J. Leopold (eds). Bulletin no. 471, New York State Museum, New York, NY. pp. 231-234.
Contributors
Judy Welles
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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