Ecological site F043AY516WA

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.

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Figure 1. Mapped extent

Areas shown in blue indicate the maximum mapped extent of this ecological site. Other ecological sites likely occur within the highlighted areas. It is also possible for this ecological site to occur outside of highlighted areas if detailed soil survey has not been completed or recently updated.

MLRA notes

Major Land Resource Area (MLRA): 043A–Northern Rocky 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.

LRU notes

Most commonly found in LRU 43A01 (Okanogan Plateau). This LRU is composed predominantly of glaciated slopes of foothills and mountains west of the Republic Graben and Sanpoil River. The LRU is in the portion of the Northern Rocky Mountains that was subjected to continental glaciation. The soils tend to be loamy andisols, mollisols and inceptisols with mixed to thick ash surfaces. Till, outwash and glacially scoured granitics are the dominant parent materials. Soil climate is a frigid or cryic temperature regime and xeric moisture regime with average annual precipitation around 450 mm (18 inches) and an average annual air temperature around 6.3 degrees C (43 degrees F). Elevation ranges from about 560 to 1530 m (2,540 to 5,020 feet).

Classification relationships

Relationship to Other Established Classifications:

United States National Vegetation Classification (2008) - A3395 Douglas fir- P. Pine / Herbaceous Understory Central Rocky Mt. Forest & Woodland Alliance

Washington Natural Heritage Program. Ecosystems of Washington State, A Guide to Identification, Rocchio and Crawford, 2015 - Northern Rocky Mt. Dry-Mesic Montane Mixed Conifer Forest (D. Fir – Pine)

Description of Ecoregions of the United States, USFS PN # 1391, 1995 - M333 Northern Rocky Mt. Forest-Steppe-Coniferous Forest-Alpine Meadow Province

Level III and IV Ecoregions of WA, US EPA, June 2010 - 15x Okanogan Highland Dry Forest. 15w Western Selkirk Maritime Forest. 15r Okanogan – Colville Xeric Valleys & Foothills.

This ecological site includes the following USDA Forest Service Plant Associations: PSME/CARU (Douglas-fir Series). (Williams et. al. 1995)

Ecological site concept

This site consists of outwash terraces (teads and risers), and footslopes of hills and mountains with the following characteristics: sandy soil materials; a water table (perched or apparent) more than 75 cm (30 in) below the soil surface during the April to October period; PSME/CARU habitat type.

Table 1. Dominant plant species

Tree	(1) Pseudotsuga menziesii var. glauca (2) Larix occidentalis
Shrub	Not specified
Herbaceous	(1) Calamagrostis rubescens (2) Carex geyeri

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Physiographic features

Physiographic Features
Landscapes: Mountains, Foothills
Landform: sideslopes, outwash terraces

Elevation: Total range = 630 to 1730 m
(2,070 to 5,670 feet)
Central tendency = 990 to 1285 m
(3,250 to 4,210 feet)

Slope (percent): Total range = 0 to 90 percent
Central tendency = 25 to 50 percent

Aspect (degrees):
35-175-310
Central tendency = 110-175-250

Table 2. Representative physiographic features

Landforms	(1) Mountains > Mountain slope (2) Foothills > Hillslope (3) Foothills > Outwash terrace
Flooding frequency	None
Ponding frequency	None
Elevation	991 – 1,283 m
Slope	25 – 50%
Water table depth	203 cm
Aspect	SE, S, SW

Table 3. Representative physiographic features (actual ranges)

Flooding frequency	Not specified
Ponding frequency	Not specified
Elevation	631 – 1,728 m
Slope	0 – 90%
Water table depth	203 cm

Climatic features

Climatic Features
Frost-free period (days): Total range = 85 to 125 days
Central tendency = 100 to 110 days

Mean annual precipitation: Total range = 340 to 725 mm
(13 to 28 inches)
Central tendency = 485 to 615 mm
(19 to 24 inches)

MAAT: Total range = 3.8 to 8.0
(39 to 46 F)
Central tendency = 5.4 to 6.4
(42 to 44 F)

Climate Stations: none

Table 4. Representative climatic features

Frost-free period (characteristic range)	100-110 days
Freeze-free period (characteristic range)
Precipitation total (characteristic range)	483-610 mm
Frost-free period (actual range)	85-125 days
Freeze-free period (actual range)
Precipitation total (actual range)	330-711 mm

Soil features

Representative Soil Features

This ecological subsite is associated with two soil series (e.g. Wapal and Sacheen). The soil components are: Vitrandic Haploxerepts, and Typic Xeropsamments. These soils have developed in mixed Mazama tephra deposits over sandy outwash. The tephra influenced layers are important for forest productivity in that they retain large amounts of water compared to other parent materials, have high cation exchange capacity and high availability of organically bound plant nutrients. The soils range from moderately deep to very deep and have low available water capacity to a depth of 1 m. The soils are well-drained.

Parent Materials:
Kind: Tephra (volcanic ash)
Origin: mixed
Kind: outwash
Origin: mixed

Surface Texture:
(1) Very Stony Ashy Coarse sandy loam
(2) Stony Ashy Coarse sandy loam
(3) Loamy sand

Fragment content of surface: 0 to 45 percent (median = 35%)

Subsurface Texture Group: Sandy
Fragment content of subsurface (10 to 150cm, weighted avg.): 6 to 14 percent (median = 14%)
Most components lack fragments on the surface
Drainage Class: Somewhat Excessively drained
Saturated Hydraulic conductivity: High
Soil Depth: >150cm (many pedons have strongly contrasting particle sizes within 30cm)
Calcium Carbonate Equivalent (percent): 0
Soil Reaction (1:1 Water): 6.1 to 7.3
Available Water Capacity (total in 100cm): 4.5 to 5.1cm (median = 5.1cm)

Table 5. Representative soil features

Parent material	(1) Volcanic ash (2) Outwash
Surface texture	(1) Ashy, very stony coarse sandy loam (2) Ashy, stony coarse sandy loam (3) Loamy sand
Drainage class	Somewhat excessively drained
Permeability class	Rapid
Depth to restrictive layer	203 cm
Soil depth	203 cm
Surface fragment cover >3"	0%
Available water capacity (0-101.6cm)	5.08 cm
Calcium carbonate equivalent (0-152.4cm)	0%
Soil reaction (1:1 water) (0-152.4cm)	Not specified
Subsurface fragment volume <=3" (10.2-152.4cm)	14%

Table 6. Representative soil features (actual values)

Drainage class	Somewhat excessively drained to excessively drained
Permeability class	Rapid to very rapid
Depth to restrictive layer	152 cm
Soil depth	152 – 203 cm
Surface fragment cover >3"	0 – 9%
Available water capacity (0-101.6cm)	4.57 – 5.08 cm
Calcium carbonate equivalent (0-152.4cm)	0%
Soil reaction (1:1 water) (0-152.4cm)	6.1 – 7.3
Subsurface fragment volume <=3" (10.2-152.4cm)	6 – 14%

Common name	Symbol	Site index low	Site index high	CMAI low	CMAI high	Age of CMAI	Site index curve code	Site index curve basis
ponderosa pine	PIPO	90	108	85	118	40	–	–
Rocky Mountain Douglas-fir	PSMEG	71	79	63	79	100	–	–
Rocky Mountain Douglas-fir	PSMEG	62	69	60	76	123	–	–
western larch	LAOC	60	70	54	73	50	–	–

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	12/22/2024
Approved by	Curtis Talbot
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 F043AY516WA

Cool-Frigid, Xeric, Sandy Outwash Terraces, mixed ash surface (Douglas-fir/Cool Dry Grass) Pseudotsuga menziesii - Calamagrostis rubescens

Last updated: 10/14/2020 Accessed: 12/22/2024