Natural Resources
Conservation Service
Ecological site F043BP901MT
Rubbly Cool Woodland Group
Last updated: 3/01/2024
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): 043B–Central Rocky Mountains
The Central Rocky Mountains (MLRA 43B) of Montana occupy some 28,850 square miles and exist primarily in Central and SW portions of the state. The climate is extremely variable with precipitation lows of 9 to 100 inches per year and frost free days of less than 30 to over 110 days. The geology of the region is also highly variable. The combination of variable climate and geology create a complex relationship of plant communities. MLRA 43B elevations typically exist between 6000 and 12,799 at Granite Peak (the highest point in Montana).
The Continental Divide runs through this MLRA effectively splitting its watershed to contribute to either the Missouri River to the East and the Columbia River to the West.
Ecological site concept
• Dominant Cover: Forest (both conifer and deciduous)
• Site does not receive any additional water
• Soils are
o Not saline or saline-sodic
o Moderately deep, deep, or very deep
o Not strongly or violently effervescent within surface mineral 4”
o Soil is not ashy or medial textural family
o Stones and/or boulders cover 50% surface area or fragmental textural class
• Soil surface texture sandy loam to loam (typically very gravelly)
• Area of rugged mountain, hills, plateaus, and valleys of the Central Rocky Mountains in Southwest Montana.
• Site landform: mountain slope, avalanche chutes
• Parent material is recent colluvium
• Moisture Regime: ustic to udic
• Temperature Regime: cryic and frigid, cool
• Elevation Range: 4590-8530 ft
• Slope: 4-70%
Associated sites
F043BP903MT |
Shallow Cool Woodland Group Shallow Cool Woodland is often above the Rubbly Cool Woodland on the landscape however variation in landforms can result in these two sites being on the same landscape position. These two sites share similar plant species however have significantly different state and transition models. |
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F043BP910MT |
Upland Cool Woodland Group The Upland Cool Woodland is a neighboring site that shares landscape position. These two sites share similar plant species however have significantly different state and transition models. |
Similar sites
F043BP903MT |
Shallow Cool Woodland Group Shallow Cool Woodland is often above the Rubbly Cool Woodland on the landscape however variation in landforms can result in these two sites being on the same landscape position. These two sites share similar plant species however have significantly different state and transition models |
---|---|
F043BP910MT |
Upland Cool Woodland Group The Upland Cool Woodland is a neighboring site that shares landscape position. These two sites share similar plant species however have significantly different state and transition models |
Table 1. Dominant plant species
Tree |
(1) Populus tremuloides |
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Shrub |
(1) Alnus incana |
Herbaceous |
(1) Achnatherum richardsonii |
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