Natural Resources
Conservation Service
Ecological site R021XY300OR
SOUTH SLOPES 10-14 PZ
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 occurs on south, southeasterly and west-facing exposures of mountain sideslopes adjacent to lake basins. Rock outcrop and rubble land are typically a component on the landscape. Slopes range from 30 to 50%. Elevations range from 4100 to 5000 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain slope
|
|---|---|
| Elevation | 1,250 – 1,524 m |
| Slope | 30 – 50% |
| Aspect | SE, S, W |
Climatic features
The annual precipitation ranges from 10 to 14 inches, most of which occurs in the form of snow during the months of October through April. The soil temperature regime is mesic with the average annual air temperature about 47 degrees F. Temperature extremes range from 100 to -30 degrees F. The frost free period is 70 to 110 days. The optimum period for plant growth is from early April to mid-June.
Table 3. Representative climatic features
| Frost-free period (average) | 110 days |
|---|---|
| Freeze-free period (average) | 0 days |
| Precipitation total (average) | 356 mm |
Figure 2. Monthly average minimum and maximum temperature
Influencing water features
Soil features
The soils of this site are well drained and contain over 35% rock fragments throughout the soil profile. The soils have a loamy surface layer and a loamy or clayey subsoil. The soils are shallow to deep over bedrock. Permeability is moderate or moderately slow. The available water holding capacity is 2 to 4 icnches. Runoff is rapid. Erosion hazard by water is moderate to severe.
Table 4. Representative soil features
| Surface texture |
(1) Loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately slow to moderate |
| Available water capacity (0-101.6cm) |
5.08 – 10.16 cm |
Ecological dynamics
The potential native plant community is dominated by a very open stand of western juniper and bluebunch wheatgrass. Bitterbrush is prominent along with other shrubs such as basin big sagebrush, wax currant, Klamath plum, desert gooseberry, buckwheat and sometimes mtn. mahogany. Other grass species present include Thurber needlegrass, sandberg bluegrass, and small patches of Idaho fescue found directly under the canopy of juniper. Common forbs include balsamroot, fleabane, phlox, yarrow, lomatium, wooly eriophyllum, lupine, hawksbeard and penstemon.
Idaho fescue is most abundant in high precipitation areas but very minor in the driest climates and more droughty positions. Bitterbrush and juniper abundance vary with time interval since burning and with site conditions. An occasional ponderosa pine is present in high precipitation areas. Locations with very high surface stones/boulders have lower production and less plant cover.
Juniper is easily damaged or killed by high intensity fires, but because of the low ground fuels and stones, most fires do not carry well leaving patches or larger areas of trees unburned. Sustained heavy grazing pressure by livestock or poor grazing management may reduce wheatgrass, fescue, needlegrass, bitterbrush, and/or palatable forbs, depending on season of use and growing conditions. Green rabbitbrush and cheatgras invade after fires and ground disturbance along with annual fescue, mustard and other weeds.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
HCPC, PSSP6/PUTR2-ARTRW8
Community 1.1
HCPC, PSSP6/PUTR2-ARTRW8
The potential native plant community is dominated by bluebunch wheatgrass and antelope bitterbrush. Vegetative composition of the community is approximately 75% grasses, 5% forbs and 20% shrubs.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
| Plant type | Low (kg/hectare) |
Representative value (kg/hectare) |
High (kg/hectare) |
|---|---|---|---|
| Grass/Grasslike | 610 | 767 | 924 |
| Shrub/Vine | 45 | 67 | 90 |
| Forb | 45 | 67 | 90 |
| Tree | 18 | 31 | 45 |
| Total | 718 | 932 | 1149 |
Figure 4. Plant community growth curve (percent production by month). OR5552, D21 Low Elev., South, Good Condition. HCPC Growth Curve.
| 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 | 15 | 30 | 45 | 10 | 0 | 0 | 0 | 0 | 0 | 0 |
Additional community tables
Table 6. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Dominant deep rooted perennial grasses | 538–673 | ||||
| bluebunch wheatgrass | PSSP6 | Pseudoroegneria spicata | 538–673 | – | ||
| 2 | Sub-dominant deep rooted perennial grasses | 36–135 | ||||
| Thurber's needlegrass | ACTH7 | Achnatherum thurberianum | 18–90 | – | ||
| Indian ricegrass | ACHY | Achnatherum hymenoides | 18–45 | – | ||
| 4 | Sub-dominant shallow rooted perennial grasses | 18–45 | ||||
| Sandberg bluegrass | POSE | Poa secunda | 18–45 | – | ||
| 5 | Other perennial grasses | 18–72 | ||||
| squirreltail | ELEL5 | Elymus elymoides | 0–6 | – | ||
| tufted wheatgrass | ELMA7 | Elymus macrourus | 0–6 | – | ||
| Idaho fescue | FEID | Festuca idahoensis | 0–6 | – | ||
| needle and thread | HECO26 | Hesperostipa comata | 0–6 | – | ||
| prairie Junegrass | KOMA | Koeleria macrantha | 0–6 | – | ||
| basin wildrye | LECI4 | Leymus cinereus | 0–6 | – | ||
|
Forb
|
||||||
| 7 | Dominant perennial forbs | 18–27 | ||||
| arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 18–27 | – | ||
| arrowleaf balsamroot | BASA3 | Balsamorhiza sagittata | 18–27 | – | ||
| 8 | Sub-dominant perennial forbs | 9–18 | ||||
| tapertip hawksbeard | CRAC2 | Crepis acuminata | 9–18 | – | ||
| 9 | Other perennial forbs | 18–45 | ||||
| common yarrow | ACMI2 | Achillea millefolium | 0–6 | – | ||
| milkvetch | ASTRA | Astragalus | 0–6 | – | ||
| buckwheat | ERIOG | Eriogonum | 0–6 | – | ||
| lupine | LUPIN | Lupinus | 0–6 | – | ||
| phlox | PHLOX | Phlox | 0–6 | – | ||
|
Shrub/Vine
|
||||||
| 12 | Sub-dominant evergreen shrubs | 9–18 | ||||
| Wyoming big sagebrush | ARTRW8 | Artemisia tridentata ssp. wyomingensis | 9–18 | – | ||
| 13 | Dominant deciduous (or 1/2 shrubs) shrubs | 18–27 | ||||
| antelope bitterbrush | PUTR2 | Purshia tridentata | 18–27 | – | ||
| 15 | Other shrubs | 18–45 | ||||
| rubber rabbitbrush | ERNA10 | Ericameria nauseosa | 0–6 | – | ||
| green rabbitbrush | ERTE18 | Ericameria teretifolia | 0–6 | – | ||
| spiny hopsage | GRSP | Grayia spinosa | 0–6 | – | ||
| wild crab apple | PERA4 | Peraphyllum ramosissimum | 0–6 | – | ||
| horsebrush | TETRA3 | Tetradymia | 0–6 | – | ||
|
Tree
|
||||||
| 16 | Dominant evergreen trees | 18–45 | ||||
| western juniper | JUOC | Juniperus occidentalis | 18–45 | – | ||
Interpretations
Animal community
The southerly aspect of this site offers warm temperatures and early spring growth that attracts several grazing and browsing forms of wildlife and gallinaceous birds in winter and spring.
Hydrological functions
The hydrologic soil groups are C and D.
Wood products
This site is susceptible to increase in western juniper. Where this has occurred the site will yield fence posts, firewood and other specialty products.
Other products
Warm temperatures and early maturing forage attract livestock to south-facing slopes in early spring. Without a grazing system that will give periodic deferment, there will be a decline in plant vigor and reproduction. Failure to manage livestock on these sites will lead to the loss of any productive value.
Other information
Invasion by western juniper and the subsequent competition for moisture will lead to a reduction of soil cover and accelerated soil loss. Improviong infiltration and permeability, and reducing runoff should be the immediate goal of juniper control. Livestock will avoid steep stony slopes and increase grazing pressure on adjacent, flatter lands. This should be considered when establishing initial stocking rates.
Supporting information
Type locality
| Location 1: Klamath County, OR | |
|---|---|
| Township/Range/Section | T36S R36E S36 |
| General legal description | East edge of Klamath Lake south of Modoc Point- T36S, R36E, Sec 36; T37S, R9E Sec 1 |
| Location 2: Klamath County, OR | |
| Township/Range/Section | T41S R13E S15 |
| General legal description | Southern end of Bryant Mountain- 41S, R13E, Sec 15 |
| Location 3: Klamath County, OR | |
| Township/Range/Section | T40S R10E S9, 16 |
| General legal description | Lower slopes of Stuckle Mtn. T40S, R10E, Sec 9, 16 |
Contributors
Barrett, Carlson
E Ersch
K.Kennedy
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) | Jeff Repp |
|---|---|
| Contact for lead author | Oregon NRCS State Rangeland Management Specialist |
| Date | 08/22/2012 |
| Approved by | Bob Gillaspy |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
None to some, moderate to severe sheet & rill erosion hazard -
Presence of water flow patterns:
Some in interspaces -
Number and height of erosional pedestals or terracettes:
None -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
10-20% -
Number of gullies and erosion associated with gullies:
None -
Extent of wind scoured, blowouts and/or depositional areas:
None, slight wind erosion hazard -
Amount of litter movement (describe size and distance expected to travel):
Fine - limited movement -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Slightly to moderately resistant to erosion: aggregate stability = 3-5 -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Shallow to deep, well drained loams and clay loams: Low OM (1-2%) -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Moderate vegetative cover (30-50%), surface rock fragments (35+%), and moderate slopes (30-50%) moderately limit rainfall impact and overland flow; infiltration is moderately slow -
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:
Bluebunch wheatgrass > Antelope bitterbrush > Wyoming big sagebrush > Thurber needlegrass > forbs > other grasses > other shrubs > Western JuniperSub-dominant:
Other:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Normal decadence and mortality expected -
Average percent litter cover (%) and depth ( in):
-
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Favorable: 1200, Normal: 800, Unfavorable: 500 lbs/acre/year at high RSI (HCPC) -
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 brush species will increase with deterioration of plant community. Western Juniper readily increases on the site. Cheatgrass and Medusahead invade sites that have lost deep rooted perennial grass functional groups. -
Perennial plant reproductive capability:
All species should be capable of reproducing annually
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