Ecological site F043AY531WA

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): 043A–Northern Rocky Mountains

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.

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

LRU notes

Most commonly found in LRU 43A01 (Okanogan Plateau) and 43A02. Climate parameters were obtained from PRISM and other models for the area. Landscape descriptors are derived from USGS DEM products and their derivatives.

Classification relationships

Relationship to Other Established Classifications:
United States National Vegetation Classification (2008) – A3362 Abies grandis – Pseudotsuga menziesii Central Rocky Mountain Forest & Woodland Alliance
Washington Natural Heritage Program. Ecosystems of Washington State, A Guide to Identification, Rocchio and Crawford, 2015 – Northern Rocky Mountain Mesic Montane Mixed Conifer Forest
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 – 15r Okanogan-Colville Xeric Valleys and Foothills, 15w Western Selkirk Maritime Forest, 15x Okanogan Highland Dry Forest, 15y Selkirk Mountains.
This ecological site includes the following USDA Forest Service Plant Association: PSME/VACA, and ABGR/VACA (Williams et. al. 1995)

Ecological site concept

The Ecological site occurs on loamy mountainsides with >7 inches of volcanic ash on the surface. A water table is at >30 inches depth and available water capacity is moderate to high. Plant communities are dominated by Douglas-fir and/or grand fir with an understory composed chiefly of huckleberry (Vaccinium) species. They occur at the elevations that mark the colder end of the frigid temperature regime or in lower positions effected by cold air drainage.

Table 1. Dominant plant species

Tree	(1) Pseudotsuga menziesii var. glauca (2) Abies grandis
Shrub	(1) Vaccinium cespitosum (2) Vaccinium membranaceum
Herbaceous	(1) Calamagrostis rubescens

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Physiographic features

Physiographic Features

These data describe the Terrace Phase of the Ecological Site see ESD F043AY531WA for a description of the Mountain phase:

Landscapes: Valleys
Landform: lower mountain slopes, outwash terraces, glaciolacustrine terraces

Elevation (m): Total range = 460 to 1000 m
(1,505 to 3,280 feet)
Central tendency = 620 to 780 m
(2,035 to 2,560 feet)

Slope (percent): Total range = 0 to 45 percent
Central tendency = 3 to 20 percent

Water Table Depth (cm): (where present water tables are perched)
70 to >200 cm
(28 to >80 inches)

Flooding:
Frequency: None
Duration: None

Ponding:
Frequency: None
Duration: None

Aspect: (central tendency)
315-15-130

Table 2. Representative physiographic features

Landforms	(1) Valley > Outwash terrace (2) Valley > Valley side (3) Valley > Lake terrace
Flooding frequency	None
Ponding frequency	None
Elevation	2,035 – 2,560 ft
Slope	3 – 20%
Water table depth	Not specified
Aspect	N, NE, E, SE

Table 3. Representative physiographic features (actual ranges)

Flooding frequency	None
Ponding frequency	None
Elevation	1,505 – 3,280 ft
Slope	45%
Water table depth	28 – 80 in

Climatic features

Climatic Features
Frost-free period (days): Total range = 95 to 140 days
Central tendency = 115 to 125 days

Mean annual precipitation (cm): Total range = 445 to 895 mm
(18 to 35 inches)
Central tendency = 560 to 705 mm
(22 to 28 inches)

MAAT (C): Total range = 5.8 to 8.9
(42 to 48 F)
Central tendency = 7.1 to 8.0
(45 to 46 F)

Climate Stations: none

Soil features

Representative Soil Features

This ecological subsite is associated with several soil components (e.g. Goddard, Louploup, Manley, Martella, Nevine, Newhorn, Parmenter, Rathdrum, Scar, and Stepstone). The soil components can be grouped into: Andic Haploxerepts, Andic Haploxeralfs, Typic Udivitrands, Xeric Vitricryands and Typic Vitrixerands. These soils have developed in Mazama tephra deposits over till, outwash and glaciolacustrine material from mixed sources. The tephra 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 adequate available water capacity to a depth of 1 m. The soils are mostly well-drained.

Parent Materials:
Kind: Tephra (volcanic ash)
Origin: mixed
Kind: till, residuum and colluvium, and outwash material
Origin: Mixed

Surface Texture: (<2mm fraction)
(1) Ashy Fine Sandy Loam
(2) Ashy Silt Loam

Fragment content of surface: 1 to 6 percent (median = 2%)

Subsurface Texture Group: Loamy
Fragment content of subsurface (25 to 100cm): 1 to 60 percent (median = 10%)
Most components lack surface fragments
Drainage Class: Well drained or Moderately well drained (15%)
Saturated Hydraulic conductivity: Moderately high to Very High
Soil Depth: 59% of components have no restriction within 150 cm
Densic contacts when present are at 50 to 130cm (median = 96cm)
Calcium Carbonate Equivalent (percent): 0 to 24 percent (median = 0)
Soil Reaction (1:1 Water): 5.1 to 8.0 (median = 6.7)
Available Water Capacity (total in 100cm): 9.15-20.65cm (median = 17.70 cm)

Table 4. Representative soil features

Parent material	(1) Volcanic ash (2) Till (3) Outwash (4) Residuum – granite and gneiss (5) Colluvium – granite and gneiss
Surface texture	(1) Ashy sandy loam (2) Ashy silt loam
Drainage class	Well drained
Permeability class	Moderate
Depth to restrictive layer	Not specified
Available water capacity (0-40in)	7 in
Calcium carbonate equivalent (0-60in)	Not specified
Soil reaction (1:1 water) (0-60in)	6.7
Subsurface fragment volume <=3" (10-40in)	10%

Table 5. Representative soil features (actual values)

Drainage class	Moderately well drained to well drained
Permeability class	Moderate to rapid
Depth to restrictive layer	20 in
Available water capacity (0-40in)	3.6 – 8.1 in
Calcium carbonate equivalent (0-60in)	Not specified
Soil reaction (1:1 water) (0-60in)	5.1 – 8
Subsurface fragment volume <=3" (10-40in)	1 – 60%

Interpretations

Wood products

Forest Site Productivity

Douglas-fir / Dwarf Huckleberry

Species Average Site Index Culmination Mean Annual Increment (CMAI) SI Reference

Ponderosa Pine 81 63 600 (Meyer, 100 yr TA)
Douglas-fir 67 70 765 (Cochran, 50 yr BH)
Western Larch 54 56 261 (Cochran, 50 yr BH)
Lodgepole Pine 69 70 520 (Alexander, 100 yr TA)

Grand fir / Dwarf Huckleberry and Grand fir / Huckelberry

Grand fir 80 57 031 (Cochran, 50 yr BH)
Western Larch 73 86 261 (Cochran, 50 yr BH)
Ponderosa pine 112 100 600 (Meyer, 100 yr TA)
Douglas-fir 78 76 765 (Cochran, 50 yr BH)
Douglas-fir 70 79 771 (Monserud, 50 yr BH)

Supporting information

References

Smith and Fischer. 1997. Fire Ecology of the Forest Habitat Types of Northern Idaho.
Williams, C.K., B.F. Kelley, B.G. Smith, and T.R. Lillybridge. October, 1995. Forested Plant Associations of the Colville National Forest.
Williams, C.K. and T.R. Lillybridge. 1983. Forested Plant Associations of the Okanogan National Forest R6-Ecol-132b-1983.
Zack, A. 1997. Biophysical Classification- Habitat Groups and Description of Northern Idaho and Northwestern Montana, Lower Clarkfork and Adjacent Areas..
. 1998. NRCS National Forestry Manual.
. 2017. NRCS Soil and Site Index data for NE WA and N. Idaho.

Approval

Curtis Talbot, 10/14/2020

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	09/12/2022
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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Ecological site F043AY531WA

Cool-Frigid, Moist-Xeric, Loamy Mountainsides, ashy surface (Douglas-fir-Grand Fir Cool Shrub) Douglas-fir-grand fir/low huckleberry-big huckleberry-dwarf huckleberry

Last updated: 10/14/2020 Accessed: 12/31/2024