Natural Resources
Conservation Service
Ecological site R043CY810OR
Open Canyon Slopes and Fans (PSSPS-SPCR)
Last updated: 9/08/2023
Accessed: 11/21/2024
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
This MLRA covers the Blue and Seven Devils Mountains of Oregon, Washington and Idaho. The area is characterized by thrust and block-faulted mountains and deep canyons composed of sedimentary, metasedimentary, and volcanic rocks. Elevations range from 1,300 to 9,800 feet (395 to 2,990 meters). The climate is characterized by cold, wet winters and cool, dry summers. Annual precipitation, mostly in the form of snow, averages 12 to 43 inches (305 to 1,090 millimeters) yet ranges as high as 82 inches (2,085 millimeters) at upper elevations. Soil temperature regimes are predominately Frigid to Cryic and soil moisture regimes are predominately Xeric to Udic. Mollisols and Andisols are the dominant soil orders. Ecologically, forests dominate but shrub and grass communities may occur on south aspects and lower elevations as well as in alpine meadow environments. Forest composition follows moisture, temperature and elevational gradients and typically ranges from ponderosa pine and Douglas-fir plant associations at lower elevations, grand fir at middle elevations and subalpine fir and Engelman spruce at upper elevations. Historical fire regimes associated with these forest types range from frequent surface fires in ponderosa pine - Douglas Fir forest types to mixed and stand replacing fire regimes in grand fir and subalpine fir types. A large percentage of the MLRA is federally owned and managed by the U.S. Forest Service for multiple uses.
Classification relationships
Plant Assoc. of Wallowa-Snake Province (R6 E 255-86)
bluebunch wheatgrass-sand dropseed-red three awn plant - GB1911
USDA Forest Service Ecological Sub-region
M332 “Blue Mountains”
U.S. National Vegetation Classification Standard (NVCS)
Group: G311. Intermountain Semi-Desert Grassland
Alliance: A3976. Pseudoroegneria spicata - Opuntia polyacantha Dry Canyon Slope Grassland Alliance
Association: CEGL001589. Aristida purpurea var. longiseta - Pseudoroegneria spicata - Sporobolus cryptandrus Grassland
Ecological site concept
This ecological site represents large areas of terraces, alluvial fans, and benches in lower elevation canyons. The historical reference community for most of these sites would be a community dominated by bluebunch wheatgrass (Pseudoroegneria spicata), Sandberg bluegrass (Poa secunda), and other dry site perennial forbs. Sand dropseed (Sporabolous cryptandrus) and red three awn (Aristida purpurea) increase with grazing. Other associated plants common to this mid seral community are annual fescues (Vulpia myuros, Vulpia microstachys), common yarrow (Achillea millefolium), shaggy fleabane (Erigeron pumilus), and woolly plantain (Plantago patagonica). Soil temperature regimes are typically mesic and soil moisture regimes are aridic or xeric bordering on aridic.
This is a provisional ecological site that groups characteristics at a broad scale with little to no field verification and is subject to extensive review and revision before final approval. All data herein was developed using existing information and literature and should be considered provisional and contingent upon field validation prior to use in conservation planning.
Associated sites
R043CY809OR |
Warm Foothills and Mountains (PSSPS-POSE) Cooler, higher elevation |
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Similar sites
R043CY809OR |
Warm Foothills and Mountains (PSSPS-POSE) Cooler, higher elevation |
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Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
Not specified |
Herbaceous |
(1) Pseudoroegneria spicata |
Click on box and path labels to scroll to the respective text.
T1a | - | Introduction of non-native species |
---|---|---|
T2a | - | Severe or continuous disturbance in the presence of non-native annual species |
R3a | - | Seeding with native perennial bunchgrasses (or non-native perennial grasses in some cases); mechanical, biological or chemical treatment of exotic species; and/or alteration of grazing management. |
State 1 submodel, plant communities
P1.1a | - | Time without fire |
---|---|---|
P1.1b | - | Extended drought in combination with disturbance |
P1.2a | - | Fire |
P1.2b | - | Fire in combination with extended drought |
P1.3a | - | Time after drought; fire cycle frequent enough to prevent expansion of shrubs |
P1.3b | - | Time after drought without fire |
State 2 submodel, plant communities
P2.1a | - | Time without fire |
---|---|---|
P2.1b | - | Extended drought in combination with disturbance |
P2.2a | - | Fire |
P2.2b | - | Fire in combination with extended drought |
P2.3a | - | Time after drought; fire cycle frequent enough to prevent expansion of shrubs |
P2.3b | - | Time after drought without fire |