Natural Resources
Conservation Service
Ecological site R010XC041OR
SR Very Shallow Rockland 12-16 PZ
Last updated: 12/13/2023
Accessed: 10/08/2024
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): 010X–Central Rocky and Blue Mountain Foothills
This MLRA is characterized by gently rolling to steep hills, plateaus, and low mountains at the foothills of the Blue Mountains in Oregon and the Central Rocky Mountains in Idaho. The geology of this area is highly varied and ranges from Holocene volcanics to Cretaceous sedimentary rocks. Mollisols are the dominant soil order and the soil climate is typified by mesic or frigid soil temperature regimes, and xeric or aridic soil moisture regimes. Elevation ranges from 1,300 to 6,600 feet (395 to 2,010 meters), increasing from west to east. The climate is characterized by dry summers and snow dominated winters with precipitation averaging 8 to 16 inches (205 to 405 millimeters) and increasing from west to east. These factors support plant communities with shrub-grass associations with considerable acreage of sagebrush grassland. Big sagebrush, bluebunch wheatgrass, and Idaho fescue are the dominant species. Stiff sagebrush, low sagebrush, and Sandberg bluegrass are often dominant on sites with shallow restrictive layers. Western juniper is one of the few common tree species and since European settlement has greatly expanded its extent in Oregon. Nearly half of the MLRA is federally owned and managed by the Bureau of Land Management. Most of the area is used for livestock grazing with areas accessible by irrigation often used for irrigated agriculture.
Classification relationships
US National Vegetation Classification:
Macrogroup: M170. Great Basin-Intermountain Dwarf Sagebrush Steppe & Shrubland
Group: G307. Columbia Plateau Scabland Dwarf-shrubland
Alliance: Eriogonum spp. / Poa secunda Dwarf-shrub Steppe Alliance
Plant Associations of the Wallowa-Snake Province:
Note: These plant associations may not represent the same buckwheat species as found on this site but are included to provide a regionally relevant reference for similar community types.
Eriogonum strictum/Poa sandbergii (ERST2/POSA3) (FM91 12)
Eriogonum douglasii/Poa sandbergii (ERDO/POSA3) (FM91 11)
Landfire Biophysical Setting Model:
Note: This model was developed specifically for the Columbia Plateau but fits the characteristics of this site very well.
0810650: Columbia Plateau Scabland Shrubland
Ecological site concept
This site occurs on convex landforms of upland plateaus with very shallow soils over hard igneous extrusive geologies (basalt, andesite, rhyolite, tuff, etc.). In the reference state, the site is characterized by buckwheat (Eriogonum spp.), Thurber’s needlegrass (Achnatherum thurberianum) and Sandberg bluegrass (Poa secunda). Areas of exposed rock and rock outcrop are common on this thin soiled site. Unlike related very shallow soil sites, a lack of deep bedrock fracturing leads to a sparse distribution of scabland sagebrush (Artemisia rigida). This is a low production site. Production is limited by the low water holding capacity of the soil. Precipitation comes in the form of snow and rain primarily in the winter and early spring. The soil profile is not able to store all the moisture that the site receives, and excess moves to adjacent sites. Historically, plant community dynamics were driven primarily by drought disturbance and very infrequent fire due to patchy fuel distribution.
Associated sites
R010XC029OR |
SR Shallow Cool 12-16 PZ SR Shallow Cool 12-16 PZ (shallow soil, higher production, different composition – ARTRV-X,T/FEID-PSSPS association) |
---|---|
R010XC033OR |
SR Cool 12-16 PZ SR Cool 12-16 PZ (moderate deep soil, higher production, different composition – ARTRV-X,T/FEID association) |
R010XC039OR |
SR Very Shallow 12-16 PZ SR Very Shallow 12-16 PZ (very shallow soil depth with a greater clay content, higher production, different composition – ARRI2/POSE-DAUN-FEID association) |
R010XC042OR |
SR Juniper Tableland 12-16 PZ SR Juniper Tableland 12-16 PZ (very shallow soil with a fractured substratum, higher production, different composition –JUOC/ARRI2/POSE association) |
R010XC047OR |
SR Mountain South 12-16 PZ SR Mountain South 12-16 PZ (moderate deep soil, south aspect, higher production, different composition – ARTRV-X,T/PSSPS association) |
R010XC054OR |
SR Mountain Shallow South 12-16 PZ SR Mountain Shallow South 12-16 PZ (shallow soil, south aspect, higher production, different composition – ARTRV-X,T/PSSPS association) |
R010XC059OR |
SR Mahogany Rockland 12+ PZ SR Mahogany Rockland 12+ PZ (shallow soil over fractured bedrock with areas of exposed rock outcrop, higher production, different composition – JUOC/CELE3-PUTR2/PSSPS-FEID association) |
R010XC068OR |
SR Cool Mountain North 12-16 PZ SR Cool Mountain North 12-16 PZ (moderate deep to deep soil, north aspect, higher production, different composition ARTRV-X,T/FEID association) |
R010XC075OR |
SR Mountain Shallow North 12-16 PZ SR Mountain Shallow North 12-16 PZ (shallow soil, north aspect higher production, different composition – ARTRV/FEID-PSSPS-POSE association) |
Similar sites
R010XC039OR |
SR Very Shallow 12-16 PZ SR Very Shallow 12-16 PZ (very shallow soil depth with a greater clay content, higher production, different composition – ARRI2/POSE-DAUN-FEID association) |
---|---|
R010XC038OR |
SR Very Shallow 9-12 PZ SR Very Shallow 9-12 PZ (lower elevation and precipitation zone, different composition – ARRI2/POSE association) |
R010XC042OR |
SR Juniper Tableland 12-16 PZ SR Juniper Tableland 12-16 PZ (very shallow soil with a fractured substratum, higher production, different composition – JUOC/ARRI2/POSE association) |
R010XC040OR |
SR Very Shallow 16-20 PZ SR Very Shallow 16-20 PZ (higher elevation, greater precipitation and production) |
Table 1. Dominant plant species
Tree |
Not specified |
---|---|
Shrub |
(1) Eriogonum |
Herbaceous |
(1) Poa secunda |
Click on box and path labels to scroll to the respective text.
Ecosystem states
T1 | - | Introduction of non-native species. |
---|---|---|
T2 | - | Catastrophic fire and soil disturbing treatments. Inappropriate grazing management in the presence of non-native annual species, may be combined with higher than normal spring precipitation. |
T3 | - | Continued inappropriate grazing management leading to excessive trampling, compaction and soil loss. |
State 1 submodel, plant communities
P1.1a | - | Low severity fire; high severity fire |
---|---|---|
P1.1b | - | Time and lack of disturbance. Excessive herbivory and/or long-term drought |
P1.2a | - | Time and lack of disturbance |
P1.3a | - | Low severity fire |
P1.3b | - | Moderate severity fire |