Natural Resources
Conservation Service

Ecological site F043CY508WA

Frigid, Xeric, Loamy, Mountains and Plateaus, Mixed Ash Surface Grand fir/pinegrass

Last updated: 9/08/2023
Accessed: 05/06/2024

Home / Esd catalog / MLRA 043C / Ecological site F043CY508WA

USC

Metric

General information

Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.

MLRA notes

Major Land Resource Area (MLRA): 043C–Blue and Seven Devils Mountains

Major land resource area (MLRA): 043C-Blue and Seven Devils Mountains

Description of MLRAs can be found in: United States Department of Agriculture, Natural Resources Conservation Service. 2006. Land Resource Regions and Major Land Resource Areas of the United States, the Caribbean, and the Pacific Basin. U.S. Department of Agriculture Handbook 296.

Available electronically at: http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/ref/?cid=nrcs142p2_053624#handbook

LRU notes

Modal LRU – 43C04 Dissected Basalt Highlands

This LRU is composed predominantly of low elevation canyons and mid elevation foothills, mountain slopes, ridges and valley walls The soils of the LRU tend to be loamy Vitrixerands, Argixerolls and Haploxerolls with thick or mixed ash surfaces. Alluvium, loess and colluvium and residuum from basalt are the dominant parent materials. Soil climate is mesic or frigid temperature regime and xeric or udic moisture regime with average annual precipitation around 905 mm (36 inches).

Others where occurring – 43C01 - Cold, Moist Volcanic Highlands

Classification relationships

This ecological site is aligned to the following classification systems:

• NVCS Central Rocky Mountain Grand fir - Douglas-fir Forest & Woodland Alliance (A- 3362).
• U.S. National Vegetation Classification Standard (NVCS) Central Rocky Mountain Grand fir-Douglas-fir-Western larch Forest Group (G211).
• Washington Natural Heritage Program code CEG000275.
• USDA Forest Service Ecological Sub-region M332 “Blue Mountains”.
• LANDFIRE BpS model 10450: Northern Rocky Mountain Dry-Mesic Montane Mixed- Conifer Forest (primary model). Note: BpS model 10500 can be used for the lodgepole pine early seral sites.
• Ecoclass Seral Stage Code CWG113 (Blue-Ochoco PA, 1991).

Ecological site concept

This ESD is distinguished by an overstory of ponderosa pine, grand fir and Douglas-fir with an understory of pinegrass and elk sedge. Shrubs such as common snowberry and Oregon grape may occur but have low coverage. Common forbs are heartleaf arnica, lupines, western hawkweed and strawberry. It occurs on foothills, mountainsides, and canyon walls This ESG fits into the National Vegetation Standard’s Central Rocky Mountain Grand Fir - Douglas-fir Forest & Woodland and Washington State’s Natural Heritage Program’s Northern Rocky Mt. Dry Mesic Montane Mixed Conifer Forest.

Associated sites

F043CY503WA	Frigid, Moist-Xeric Loamy, Canyons and Mountains (Grand fir/Moist Shrub) frigid, moist-xeric, ashy surface, basalt/andesite geology.
F043CY504WA	Warm-Frigid, Xeric, Loamy, Basalt Mountains and Plateaus (Douglas-fir/warm dry shrub) warm-frigid, xeric, mixed ash surface, basalt geology.

F043CY503WA

Frigid, Moist-Xeric Loamy, Canyons and Mountains (Grand fir/Moist Shrub)

frigid, moist-xeric, ashy surface, basalt/andesite geology.

F043CY504WA

Warm-Frigid, Xeric, Loamy, Basalt Mountains and Plateaus (Douglas-fir/warm dry shrub)

warm-frigid, xeric, mixed ash surface, basalt geology.

Similar sites

F043CY509WA	Frigid, Xeric, Loamy Mountains and Plateaus, Ashy Surface Grand fir/pinegrass Ashy surface
F043CY503WA	Frigid, Moist-Xeric Loamy, Canyons and Mountains (Grand fir/Moist Shrub) Moist-xeric soil moisture regime
F043CY502WA	Cool-Frigid, Dry-Xeric, Loamy Mountains (Douglas-fir Cool Dry Grass) Cool-frigid soil temperature regime, dry-xeric soil moisture regime

F043CY509WA

Frigid, Xeric, Loamy Mountains and Plateaus, Ashy Surface Grand fir/pinegrass

Ashy surface

F043CY503WA

Frigid, Moist-Xeric Loamy, Canyons and Mountains (Grand fir/Moist Shrub)

Moist-xeric soil moisture regime

F043CY502WA

Cool-Frigid, Dry-Xeric, Loamy Mountains (Douglas-fir Cool Dry Grass)

Cool-frigid soil temperature regime, dry-xeric soil moisture regime

Table 1. Dominant plant species

Tree	(1) Abies grandis (2) Pseudotsuga menziesii var. glauca
Shrub	(1) Chimaphila umbellata (2) Mahonia repens
Herbaceous	(1) Calamagrostis rubescens (2) Carex geyeri

Download full description

Physiographic features

Physiographic Features
Landscapes: Mountains, Plateaus
Landform: Mountain slopes, Plateaus

Elevation (m): Total range = 735 to 1860 m
(2,410 to 6,100 feet)
Central tendency = 1150 to 1435 m
(3,770 to 4,705 feet)

Slope (percent): Total range = 20 to 100 percent
Central tendency = 55 to 75 percent

Water Table Depth (cm):
>200 cm (median = >200cm)
>80 inches; (median = >80 inches)

Flooding:
Frequency: None
Duration: None

Ponding:
Frequency: None
Duration: None

Aspect:
Total range: 240-0-170
Central tendency: 280-0-80

Table 2. Representative physiographic features

Landforms	(1) Mountains > Mountain slope (2) Plateau > Plateau
Flooding frequency	None
Ponding frequency	None
Elevation	3,770 – 4,705 ft
Slope	55 – 75%
Water table depth	Not specified
Aspect	W, NW, N, NE

Table 3. Representative physiographic features (actual ranges)

Flooding frequency	Not specified
Ponding frequency	Not specified
Elevation	2,410 – 6,100 ft
Slope	20 – 100%
Water table depth	Not specified

Climatic features

Climatic Features
Frost-free period (days): Total range = 65 to 125 days
Central tendency = 75 to 95 days

Mean annual precipitation (cm): Total range = 450 to 1560 mm
(18 to 61 inches)
Central tendency = 845 to 1225 mm
(33 to 48 inches)

MAAT (C): Total range = 4.9 to 9.1
(41 to 48 F)
Central tendency = 6.7 to 7.9
(44 to 46 F)

Climate Stations: none

Table 4. Representative climatic features

Frost-free period (characteristic range)	75-95 days
Freeze-free period (characteristic range)
Precipitation total (characteristic range)	31-48 in
Frost-free period (actual range)	65-125 days
Freeze-free period (actual range)
Precipitation total (actual range)	18-61 in
Frost-free period (average)	85 days
Freeze-free period (average)
Precipitation total (average)	40 in

Soil features

This ecological subsite is associated with several soil series (e.g. Kamela, Klickson, Larabee, Lamulita). The soil components are: Vitrandic Argixerolls and Vitrandic Haploxerepts. These soils have developed in highly mixed Mazama tephra deposits and loess, over residuum and colluvium from basalt or andesite. The soils are moderately deep to very deep and have adequate available water capacity to a depth of 1 m. The soils are well-drained.

Parent Materials:
Kind: Tephra (volcanic ash), loess
Origin: mixed
Kind: residuum and colluvium,
Origin: basalt or andesite

Surface Texture:
(1) Ashy Silt loam
(2) Very Gravelly Ashy loam
(3) Cobbly Ashy loam
(4) Ashy Clay loam

Table 5. Representative soil features

Parent material	(1) Volcanic ash (2) Loess (3) Residuum – basalt (4) Colluvium – basalt (5) Residuum – andesite (6) Colluvium – andesite
Surface texture	(1) Ashy silt loam (2) Ashy loam (3) Ashy clay loam
Drainage class	Well drained
Permeability class	Moderately slow
Depth to restrictive layer	38 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	4.8 in
Calcium carbonate equivalent (0-60in)	Not specified
Soil reaction (1:1 water) (0-60in)	Not specified
Subsurface fragment volume <=3" (10-60in)	20%
Subsurface fragment volume >3" (10-60in)	25%

Table 6. Representative soil features (actual values)

Drainage class	Well drained
Permeability class	Slow to moderate
Depth to restrictive layer	20 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	3.5 – 6.2 in
Calcium carbonate equivalent (0-60in)	Not specified
Soil reaction (1:1 water) (0-60in)	5.6 – 7.3
Subsurface fragment volume <=3" (10-60in)	3 – 50%
Subsurface fragment volume >3" (10-60in)	6 – 80%

Ecological dynamics

ECOLOGICAL DYNAMICS OF THE SITE
This site is almost exclusively made up of the grand fir (Abies grandis)/pinegrass (Calamagrostis rubescens) plant association (ABGR/CARU). Very minor occurrences of the grand fir/elk sedge (Carex geyeri) (ABGR/CAGE) plant association, and cold pocket lodgepole pine (Pinus contorta) may be found together with with the major plant association. ABGR/CARU is a part of the broader warm dry upland forest plant association group (PAG), and the dry upland forest potential vegetation group (PVG) 1.
This dry grand fir forest type occurs above Ponderosa pine (Pinus ponderosa) forest types on a moisture gradient. It is in turn transitional to the mesic mixed (in LANDFIRE2 terminology) conifer types. In the historic, naturally occurring ecological condition, Ponderosa pine is usually the long-lived dominant species in a fire-maintained stand. Other conifers found in this ecologic site include grand fir, Douglas-fir (Pesudotsuga menziesii) and western larch (Larix occidentalis). Western larch is commonly limited in diameter growth due to the late season temperature/moisture limitations which occur within this seasonally dry ecological site.
Frequent, low intensity surface fires (also called “under-burns”) maintained widely spaced stands of fire-resistant conifers in older, more open stands. Less frequently occurring mixed-severity and stand replacement fires resulted in mosaics of older and larger trees, intermingled with younger patches of regenerating forests. The early development (i.e. regeneration) phase of this ecological site was dominated by Ponderosa pine and larch seedlings, mixed with fire tolerant grasses, sedges and shrub species such as ceanothus spp., scouler willow (Salix scouleriana) and Bromus spp.
Young, newly regenerated stands would usually progress to mid-development phases in time. The stands were dominated by large pole to small and intermediate sawtimber sized individual conifers. Individual stands expressed varying degrees of canopy closure(s) depending on initial seedling and stocking rates, coupled with the impacts of disturbance events that occurred over the course of development. Mid-development stands could in turn progress to mature stands with the passing of additional time and under favorable conditions. In the absence of surface fire, shade tolerant grand fir will begin to dominate the understory conifer layer (this is now a common and wide spread condition, the direct result of a policy of total fire suppression which was implemented in the Post-European era of settlement in the western United States).
Although fire was the major disturbance factor in the historic context in this ecological site, insects (such as bark beetles and defoliators) and root diseases also impacted the forest at any given time. Less frequent wind events and lighting also occurred, locally altering stand structural and functional attributes.

State and transition model

Custom diagram

Standard diagram

More interactive model formats are also available. View Interactive Models

Supporting information

References

Powell, D.C., C.G. Johnson, E.A. Crowe, A. Wells, and D.K. Swanson. 2007. Potential vegetation hierarchy for the Blue Mountains section of northeastern Oregon, southeastern Washington, and west-central Idaho. Gen. Tech. Rep. PNW-GTR-709.. U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station., Portland, OR.

Other references

USNVC [United States National Vegetation Classification]. 2020. United States National Vegetation Classification Database, V2.03. Federal Geographic Data Committee, Vegetation Subcommittee, Washington DC. USNVC: http://usnvc.org/

Contributors

Frank Gariglio
Brian Gardner

Approval

Kirt Walstad, 9/08/2023

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	09/09/2023
Approved by	Kirt Walstad
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:

Download reference sheet

Search

Natural ResourcesConservation Service