Ecological site F043CY505WA

F043CY506WA	Warm-Frigid, Xeric Loamy, Granitic, Mountains (Douglas-fir/ warm dry shrub) warm-frigid, xeric, mixed ash and loess, granitic geology.
F043CY507WA	Warm-Frigid, Xeric Loamy, Hills and Plateaus, High WT (Douglas-fir/ warm dry shrub) warm-frigid, xeric, mixed ash and loess, perched water table at 18 to 36 inches during Feb-May.

F043CY507WA	Warm-Frigid, Xeric Loamy, Hills and Plateaus, High WT (Douglas-fir/ warm dry shrub) Site has a perched water table at 18 to 36 inches during Feb-May
F043CY504WA	Warm-Frigid, Xeric, Loamy, Basalt Mountains and Plateaus (Douglas-fir/warm dry shrub) Basalt geology
F043CY506WA	Warm-Frigid, Xeric Loamy, Granitic, Mountains (Douglas-fir/ warm dry shrub) Granitic geology

Tree	(1) Pseudotsuga menziesii var. glauca (2) Pinus ponderosa
Shrub	(1) Physocarpus malvaceus (2) Symphoricarpos albus
Herbaceous	(1) Calamagrostis rubescens (2) Arnica cordifolia

Landforms	(1) Foothills > Hillslope (2) Foothills > Ridge (3) Foothills > Plateau
Flooding frequency	None
Ponding frequency	None
Elevation	3165 – 3790 ft
Slope	10 – 45 %
Water table depth	0 in
Aspect	NW, N, NE, E

Flooding frequency	Not specified
Ponding frequency	Not specified
Elevation	2230 – 4590 ft
Slope	0 – 95 %
Water table depth	0 – 18 in

Frost-free period (characteristic range)	100-120 days
Freeze-free period (characteristic range)
Precipitation total (characteristic range)	30-40 in
Frost-free period (actual range)	80-140 days
Freeze-free period (actual range)
Precipitation total (actual range)	20-50 in
Frost-free period (average)	110 days
Freeze-free period (average)
Precipitation total (average)	40 in

Parent material	(1) Volcanic ash (2) Loess (3) Residuum – basalt
Surface texture	(1) Silt loam (2) Silty clay loam
Drainage class	Well drained
Permeability class	Moderately slow to moderate
Depth to restrictive layer	46 – 60 in
Soil depth	46 – 60 in
Surface fragment cover <=3"	Not specified
Surface fragment cover >3"	Not specified
Available water capacity (0-40in)	7.9 in
Soil reaction (1:1 water) (0-60in)	7
Subsurface fragment volume <=3" (10-60in)	1 %
Subsurface fragment volume >3" (10-60in)	Not specified

Drainage class	Moderately well drained to well drained
Permeability class	Very slow to moderate
Depth to restrictive layer	20 – 80 in
Soil depth	20 – 80 in
Surface fragment cover <=3"	0 %
Surface fragment cover >3"	0 %
Available water capacity (0-40in)	5.8 – 7.9 in
Soil reaction (1:1 water) (0-60in)	6.1 – 7.3
Subsurface fragment volume <=3" (10-60in)	0 – 15 %
Subsurface fragment volume >3" (10-60in)	0 – 30 %

Ecological dynamics

This site is comprised of the modal Douglas-fir (Pseutotsuga menziesii)/ninebark (Physocarpus malvaceus) plant association (PSME/PHMA). The less abundant Douglas-fir/Common Snowberry (Symphoricarpos albus) (PSME/SYAL) and Douglas-fir/birchleaf spirea (Spirea betulifolia) (PSME/SPBE) plant associations are included in this provisional ESD. These plant associations are all part of the broader warm dry upland forest plant association group (PAG), and the dry upland forest potential vegetation group (PVG) .This warm dry Douglas-fir forest type occurs above Ponderosa pine (Pinus ponderosa) forest types on a moisture gradient. It is in turn transitional to the mesic mixed (using LANDFIRE terminology; generally, “moderately dry”) conifer types.
This ESD was characterized by a ponderosa pine dominated overstory in the historic, naturally occurring ecological condition. Older stands typically contained large, widely spaced ponderosa pine and Douglas-fir, with understory shrub species such as ninebark, ocean spray (Holodiscus discolor), and snowberry.
Other conifers found in this ecologic site include grand fir (to a limited extent) and western larch (Larix occidentalis). Larch begins to occur in greater proportions compared to the dryer and warmer grass dominated Douglas-fir plant associations (such as in the pinegrass and elk sedge plant association environments).
Pre-European frequent, low intensity surface fires (also called “under-burns”) maintained long lived stands of fire-resistant late seral conifers in the older, more open stands. Less frequent 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 recruitment and lesser numbers of larch seedlings, occurring with fire adapted understory species such as ceanothus spp., Scouler’s willow (Salix scouleriana), ninebark, and grass species including pinegrass and elk sedge.
Young, newly regenerated stands would normally progress to mid-development phases in time, in the absence of major disturbance impacts that would halt progression. Those developing stands were dominated by large pole to small and intermediate sawtimber sized individual conifers . The stands expressed varying degrees of canopy closure depending on the initial seedling and stocking rates, coupled with the impacts of minor, small scale 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 significant surface fire, shade tolerant grand fir will begin to dominate the understory conifer layer (understory infill of mid and late seral conifers is now a common, widespread condition which is a direct result of a policy of total fire suppression. The policy of total forest fire suppression was implemented in the Post-European era of settlement in the western United States and became progressively effective in extinguishing the majority of wildfires across dry western landscapes.
The expressions of the various historical stand(s) in this site contained various ages, sizes and species mixes which were found in a mosaic pattern across the larger landscape. Clumps, gaps and individual trees were the norm. These forests occurred in ecologically defined “spatially heterogeneous patterns”.
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 of the stand.

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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	07/15/2026
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 F043CY505WA

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

Last updated: 9/08/2023 Accessed: 07/15/2026

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Ecological site concept

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Table 1. Dominant plant species

Natural Resources
Conservation Service

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

Last updated: 9/08/2023
Accessed: 07/15/2026