Natural Resources
Conservation Service
Ecological site R223XY801AK
Alpine terrain Cryumbrets and Eutrocryept, high elevation
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.
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.
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
Not specified |
Physiographic features
This site includes well drained, alpine soils on high mountain peaks, ridges, slopes, and basins in the Talkeetna Mountains, above 2000 feet (610 m) elevation. Alpine terrain includes that portion of the alpine zone not included in ecological sites Alpine hummocks and Alpine ridges. Slope ranges up to 100 percent or more. Miscellaneous land types associated with this site are rock outcrops, cliffs, talus, and boulder fields.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain
|
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 1,952 – 5,097 ft |
| Slope | 25 – 70% |
| Water table depth | 60 in |
| Aspect | E, S, W |
Climatic features
Influencing water features
Soil features
Cryumbrepts component is on a mountain. The parent material consists of gravelly colluvium and/or silty loess over gravelly colluvium. The runoff class is high. The depth to restrictive layer is greater than 60 inches to bedrock. It is well drained. The slowest permeability of the soil material is slow. Available water capacity is very low and shrink swell potential is low. This soil is not flooded and is not ponded. The water table is deeper than 6 feet. There are no saline horizons within 30 inches of the soil surface. There are no sodic horizons within 30 inches of the soil surface. It is in nonirrigated land capability class 7e.
Eutrocryepts, high elevation component is on mountains. The parent material consists of gravelly colluvium. The runoff class is high. The depth to restrictive layer is greater than 80 inches. It is well drained. The slowest permeability of the soil material is moderately slow. Available water capacity is high and shrink swell potential is low. This soil is not flooded and is not ponded. The water table is deeper than 6 feet. It is in nonirrigated land capability class 7e.
Table 3. Representative soil features
| Surface texture |
(1) Very cobbly sandy loam (2) Silt loam (3) Very fine sandy loam |
|---|---|
| Drainage class | Well drained |
| Permeability class | Slow to moderately slow |
| Soil depth | 8 – 60 in |
| Surface fragment cover <=3" | Not specified |
| Surface fragment cover >3" | 45% |
| Available water capacity (0-40in) |
1 – 9 in |
| Calcium carbonate equivalent (0-40in) |
Not specified |
| Electrical conductivity (0-40in) |
Not specified |
| Sodium adsorption ratio (0-40in) |
Not specified |
| Soil reaction (1:1 water) (0-40in) |
4 – 7.3 |
| Subsurface fragment volume <=3" (Depth not specified) |
Not specified |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
No disturbance pathways were observed. Two potential plant communities co-exist on this site. They are found in a "mosaic" and are co-dependent with each other but are not succession or disturbance dependent on each other. In this case two 1.1 plant communities are identified in the STM. 1.1 Low growing dwarf shrub/forb will be considered the 1.2 plant community in order to capture in ESIS.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference
Community 1.1
Low growing dwarf shrub/grass
Vegetation varies in response to slope, aspect, soil depth and drainage, wind patterns, and snow avalanching and accumulation; and includes a variety of alpine dwarf scrub and herbaceous types.
Table 4. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 1-45% |
| Grass/grasslike foliar cover | 1-40% |
| Forb foliar cover | 5-50% |
| Non-vascular plants | 0% |
| Biological crusts | 5% |
| Litter | 85% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 1% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 0% |
Table 5. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 1-45% | 1-5% | – |
| >0.5 <= 1 | – | – | 40-40% | 5-50% |
| >1 <= 2 | – | – | – | – |
| >2 <= 4.5 | – | – | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 2. Plant community growth curve (percent production by month). AK0022, Southern. 60-200 days.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 0 | 0 | 0 | 0 | 10 | 30 | 45 | 10 | 5 | 0 | 0 | 0 |
Community 1.2
Low growing dwarf shrub/Forb
This plant community is considered a 1.1 potential. It occurs with the grassy 1.1 site in a "mosaic" pattern. This plant community will be associated with the 1.1 Low growing dwarf shrub/forb in the STM.
Table 6. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 3-50% |
| Grass/grasslike foliar cover | 1-2% |
| Forb foliar cover | 1-20% |
| Non-vascular plants | 10% |
| Biological crusts | 0% |
| Litter | 2% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 0% |
Table 7. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | 3-50% | 1-2% | 1-20% |
| >0.5 <= 1 | – | – | – | – |
| >1 <= 2 | – | – | – | – |
| >2 <= 4.5 | – | – | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 3. Plant community growth curve (percent production by month). AK0022, Southern. 60-200 days.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| J | F | M | A | M | J | J | A | S | O | N | D |
| 0 | 0 | 0 | 0 | 10 | 30 | 45 | 10 | 5 | 0 | 0 | 0 |
Additional community tables
Table 8. Community 1.1 forest understory composition
| Common name | Symbol | Scientific name | Nativity | Height (ft) | Canopy cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/grass-like (Graminoids)
|
||||||
| bluejoint | CACA4 | Calamagrostis canadensis | Native | – | 40 | |
|
Shrub/Subshrub
|
||||||
| partridgefoot | LUPE | Luetkea pectinata | Native | – | 45 | |
Table 9. Community 1.2 forest understory composition
| Common name | Symbol | Scientific name | Nativity | Height (ft) | Canopy cover (%) | |
|---|---|---|---|---|---|---|
|
Forb/Herb
|
||||||
| bunchberry dogwood | COCA13 | Cornus canadensis | Native | – | 20 | |
|
Shrub/Subshrub
|
||||||
| partridgefoot | LUPE | Luetkea pectinata | Native | – | 50 | |
Interpretations
Supporting information
Contributors
Dennis Moore
Dkautz
Michelle Schuman
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 | |
| Approved by | |
| 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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