Natural Resources
Conservation Service
Ecological site R226XY001AK
Maritime Herbaceous Peat Slope
Accessed: 12/03/2024
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.
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Salix arctica |
| Herbaceous |
(1) Calamagrostis canadensis |
Physiographic features
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain slope
|
|---|---|
| Flooding frequency | None |
| Ponding frequency | None |
| Elevation | 1,500 – 2,500 ft |
| Slope | 25 – 35% |
| Water table depth | 60 in |
| Aspect | N, NW |
Climatic features
Influencing water features
Soil features
No place for Soil Component Name, Map Unit Name, Soil Family, etc.
No Organics in Texture0
Table 3. Representative soil features
| Parent material |
(1)
Volcanic ash
–
acidic volcanic breccia
|
|---|---|
| Surface texture |
(1) Peat |
| Family particle size |
(1) Loamy |
| Drainage class | Somewhat poorly drained to poorly drained |
| Permeability class | Moderately slow to slow |
| Soil depth | 60 in |
| Surface fragment cover <=3" | Not specified |
| Surface fragment cover >3" | Not specified |
| Electrical conductivity (0-40in) |
1 mmhos/cm |
| Subsurface fragment volume <=3" (Depth not specified) |
Not specified |
| Subsurface fragment volume >3" (Depth not specified) |
Not specified |
Ecological dynamics
This site is completely undisturbed. History of volcanic activity on Attu. No anthropogenic although the area was active during WWII and signs of cultural significance, primarily due to steepness of the site.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference
Attu undisturbed, natural benchmark state
Community 1.1
Willow-bluejoint herbaceous
Tall willow dominated with bluejoint grass and a mixture of herbaceous species.
Figure 1. Annual production by plant type (representative values) or group (midpoint values)
Table 4. Annual production by plant type
| Plant type | Low (lb/acre) |
Representative value (lb/acre) |
High (lb/acre) |
|---|---|---|---|
| Forb | 0 | 0 | 0 |
| Grass/Grasslike | 0 | 0 | 0 |
| Shrub/Vine | 0 | 0 | 0 |
| Total | – | – | – |
Table 5. Ground cover
| Tree foliar cover | 0% |
|---|---|
| Shrub/vine/liana foliar cover | 55-80% |
| Grass/grasslike foliar cover | 50-75% |
| Forb foliar cover | 25-35% |
| Non-vascular plants | 0% |
| Biological crusts | 0% |
| Litter | 25-35% |
| Surface fragments >0.25" and <=3" | 0% |
| Surface fragments >3" | 0% |
| Bedrock | 0% |
| Water | 0% |
| Bare ground | 0% |
Table 6. Canopy structure (% cover)
| Height Above Ground (ft) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.5 | – | – | – | – |
| >0.5 <= 1 | – | – | – | – |
| >1 <= 2 | – | – | 50-75% | 25-35% |
| >2 <= 4.5 | – | 55-80% | – | – |
| >4.5 <= 13 | – | – | – | – |
| >13 <= 40 | – | – | – | – |
| >40 <= 80 | – | – | – | – |
| >80 <= 120 | – | – | – | – |
| >120 | – | – | – | – |
Figure 2. Plant community growth curve (percent production by month). AK0226, Aleutians. Growing days 115 to 140.
| 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 | 5 | 15 | 30 | 30 | 10 | 10 | 0 | 0 | 0 |
Additional community tables
Table 7. 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 | – | 50–75 | |
|
Shrub/Subshrub
|
||||||
| arctic willow | SAAR27 | Salix arctica | – | – | 55–80 | |
Interpretations
Supporting information
Contributors
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) | Schuman |
|---|---|
| Contact for lead author | NRCS MO170 |
| Date | 06/09/2010 |
| Approved by | Schuman |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
0 -
Presence of water flow patterns:
0 -
Number and height of erosional pedestals or terracettes:
0 -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
0 -
Number of gullies and erosion associated with gullies:
0 -
Extent of wind scoured, blowouts and/or depositional areas:
0 -
Amount of litter movement (describe size and distance expected to travel):
0 -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
0 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
0 -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
None -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
none -
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:
naSub-dominant:
naOther:
naAdditional:
na -
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
0 -
Average percent litter cover (%) and depth ( in):
na -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
na -
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:
na -
Perennial plant reproductive capability:
na
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