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Natural Resources
Conservation Service
Ecological site R226XY086AK
Rubble Lava Flow (AK653 St Paul Island)
Accessed: 08/17/2024
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 |
Not specified |
Herbaceous |
Not specified |
Physiographic features
This site occurs as a lava flow on the western part of the island. Vegetated areas are interspersed throughout the site.
Table 2. Representative physiographic features
Landforms |
(1)
Lava flow
|
---|---|
Elevation | 12 – 91 m |
Slope | 0 – 60% |
Climatic features
Table 3. Representative climatic features
Frost-free period (average) | 120 days |
---|---|
Freeze-free period (average) | 100 days |
Precipitation total (average) | 610 mm |
Figure 1. Monthly precipitation range
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Soil features
Soils are shallow and well drained. Soils are very high in organic matter content and soil pH is moderately acid. Runoff is low and permeability is very slow.
Table 4. Representative soil features
Surface texture |
(1) Cobbly silt (2) Mucky |
---|---|
Family particle size |
(1) Loamy |
Drainage class | Well drained |
Permeability class | Very slow |
Soil depth | 25 – 51 cm |
Surface fragment cover <=3" | 0% |
Surface fragment cover >3" | 0% |
Available water capacity (0-101.6cm) |
21.84 – 22.35 cm |
Calcium carbonate equivalent (0-101.6cm) |
0% |
Electrical conductivity (0-101.6cm) |
0 mmhos/cm |
Sodium adsorption ratio (0-101.6cm) |
0 |
Soil reaction (1:1 water) (0-101.6cm) |
5.6 – 6 |
Subsurface fragment volume <=3" (Depth not specified) |
0% |
Subsurface fragment volume >3" (Depth not specified) |
0% |
Ecological dynamics
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Empetrum nigrum/Lupinus nootkatensis
Community 1.1
Empetrum nigrum/Lupinus nootkatensis
Shrubs make up about 60% of the composition, forbs about 30% and grasses and sedges 10% of the composition. Total annual vascular herbage production is 1380 pounds/acre. Total live lichen biomass is 5000 pounds/acre.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Additional community tables
Table 5. Community 1.1 plant community composition
Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
---|---|---|---|---|---|---|
Shrub/Vine
|
||||||
1 | 953–1009 | |||||
black crowberry | EMNI | Empetrum nigrum | 532–560 | – | ||
arctic willow | SAAR27 | Salix arctica | 375–387 | – | ||
northern willow | SAAR6 | Salix arctophila | 50–62 | – | ||
northern mountain cranberry | VAVIM | Vaccinium vitis-idaea ssp. minus | 0–1 | – | ||
cloudberry | RUCH | Rubus chamaemorus | 0–1 | – | ||
Grass/Grasslike
|
||||||
1 | 140–196 | |||||
sedge | CAREX | Carex | 34–45 | – | ||
wideleaf polargrass | ARLA2 | Arctagrostis latifolia | 22–34 | – | ||
bluejoint | CACAL3 | Calamagrostis canadensis var. langsdorffii | 22–34 | – | ||
common woodrush | LUMU2 | Luzula multiflora | 17–28 | – | ||
alpine fescue | FEBR | Festuca brachyphylla | 6–17 | – | ||
Alaska fescue | FEBR2 | Festuca brevissima | 0–11 | – | ||
Kentucky bluegrass | POPR | Poa pratensis | 0–11 | – | ||
spike trisetum | TRSP2 | Trisetum spicatum | 6–11 | – | ||
smallflowered woodrush | LUPA4 | Luzula parviflora | 6 | – | ||
alpine timothy | PHAL2 | Phleum alpinum | 0–6 | – | ||
bluegrass | POA | Poa | 0–6 | – | ||
Bering's tufted hairgrass | DEBE2 | Deschampsia beringensis | 0–6 | – | ||
mountain harebell | CALA7 | Campanula lasiocarpa | 0–1 | – | ||
shortstalk sedge | CAPO | Carex podocarpa | 0–1 | – | ||
Siberian oatgrass | TRSI2 | Trisetum sibiricum | 0–1 | – | ||
Forb
|
||||||
1 | 392–420 | |||||
Nootka lupine | LUNO | Lupinus nootkatensis | 247–258 | – | ||
seacoast angelica | ANLU | Angelica lucida | 56–62 | – | ||
woodfern | DRYOP | Dryopteris | 39–50 | – | ||
boreal sagebrush | ARAR9 | Artemisia arctica | 6–17 | – | ||
Pacific hemlockparsley | COGM | Conioselinum gmelinii | 11–17 | – | ||
whorled lousewort | PEVE | Pedicularis verticillata | 6–11 | – | ||
Bering chickweed | CEBEG3 | Cerastium beeringianum ssp. beeringianum var. grandiflorum | 6–11 | – | ||
Danish scurvygrass | COGR6 | Cochlearia groenlandica | 0–6 | – | ||
Lapland cornel | COSU4 | Cornus suecica | 0–1 | – | ||
boreal draba | DRBO | Draba borealis | 0–1 | – | ||
larkspurleaf monkshood | ACDE2 | Aconitum delphiniifolium | 0–1 | – | ||
larkspurleaf monkshood | ACDEC | Aconitum delphiniifolium ssp. chamissonianum | 0–1 | – | ||
boreal yarrow | ACMIB | Achillea millefolium var. borealis | 0–1 | – | ||
sweetflower rockjasmine | ANCH | Androsace chamaejasme | 0–1 | – | ||
arctic stitchwort | MIAR3 | Minuartia arctica | 0–1 | – | ||
Bering chickweed | CEBE2 | Cerastium beeringianum | 0–1 | – | ||
Hornemann's willowherb | EPHOB | Epilobium hornemannii ssp. behringianum | 0–1 | – | ||
whitish gentian | GEAL2 | Gentiana algida | 0–1 | – | ||
villous cinquefoil | POVI4 | Potentilla villosa | 0–1 | – | ||
moss campion | SIAC | Silene acaulis | 0–1 | – | ||
northern starwort | STCA | Stellaria calycantha | 0–1 | – | ||
arctic starflower | TREU | Trientalis europaea | 0–1 | – | ||
arctic starflower | TREUA | Trientalis europaea ssp. arctica | 0–1 | – | ||
alpine violet | VILA10 | Viola labradorica | 0–1 | – | ||
common chickweed | STME2 | Stellaria media | – | – | ||
alpine bistort | POVI3 | Polygonum viviparum | – | – | ||
Lichen
|
||||||
1 | 0–11 | |||||
whiteworm lichen | THAMN3 | Thamnolia | 0–11 | – |
Interpretations
Animal community
This site provides high value winter forage for reindeer. Willow growing on this site is also high forage value during the winter and early spring months.
Supporting information
Contributors
Swanson
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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