Natural Resources
Conservation Service
Ecological site R009XY010ID
South Slope Schist
16-22 PZ PSSPS-POSE
Last updated: 9/23/2020
Accessed: 04/21/2026
-
Search
Major Land Resource Area or ecological site by name and/or ID.
PreviousSectionsNextGeneral 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.
Classification relationships
No data.
Associated sites
R009XY002ID North Slope Loamy 16-22 PZ
R009XY003ID Loamy 16-22 PZ
R009XY004ID South Slope Loamy 16-22 PZ
R009XY008ID Schist 16-22 PZ PSSPS-FEID
R009XY009ID North Slope Schist 16-22 PZ FEID-PSSPS
Similar sites
R009XY008ID Schist 16-22 PZ PSSPS-FEID
Table 1. Dominant plant species
Tree Not specified
Shrub Not specified
Herbaceous Not specified
Physiographic features
This site occurs on steep south and west facing slopes of 30-70 percent. Elevations usually range from 1800-4000 feet (550-1200 meters).
Table 2. Representative physiographic features
Landforms (1) Canyon
(2) Steptoe
Elevation 1800 – 4000 ft Slope 30 – 70 % Water table depth 60 – 0 in Aspect S, W Climatic features
The elevation of MLRA 9 ranges from 2000 to 4000 feet with an average elevation of 3000 feet. Elevation along major streams averages only 650 feet above sea level. Average annual precipitation ranges from 20 to 25 inches with an average of 23 based on 9 long term climate stations located throughout the MLRA. Summers are relatively dry while precipitation is evenly distributed between fall, winter, and spring.
The maximum average annual temperature is 58 degrees Fahrenheit while the average minimum temperature is 35 degrees F. The average annual temperature is 46.8 degrees F. The frost free period ranges from 107 to 134 days and the freeze free period ranges from 143 to 173 days.
Table 3 Representative climatic features
Frost-free period (average) 130 days Freeze-free period (average) 170 days Precipitation total (average) 30 in BarLineFigure 1. Monthly precipitation range
BarLineFigure 2. Monthly average minimum and maximum temperature
">Influencing water features
This site is not influenced by adjacent wetlands, streams, or run-on.
Soil features
The soils are well drained shallow to moderately deep flaggy and stony or channery loams formed and developed over decomposed schist bedrock. Lime is often present in the profile. Available water capacity is low to moderate and permeability is moderate to moderately slow. The surface layers are slightly acid to neutral. These soils are characterized by xeric moisture and mesic temperature regimes.
Table 4. Representative soil features
Surface texture (1) Gravelly loam
(2) Very gravelly loamy sand
Family particle size (1) Loamy
Drainage class Well drained Permeability class Moderately slow Soil depth 40 – 60 in Surface fragment cover <=3" 5 – 40 % Surface fragment cover >3" 0 – 5 % Available water capacity
(0-40in)3.1 – 7.1 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)5.6 – 7.3 Subsurface fragment volume <=3"
(Depth not specified)10 – 50 % Subsurface fragment volume >3"
(Depth not specified)5 – 30 % Ecological dynamics
The dominant visual aspect of this site is grassland with bluebunch wheatgrass dominant. Composition by weight is approximately 75-85% grass, 15-25% forbs, and a T-3% shrubs.
During the last few thousand years, this site has evolved in a semi-arid climate characterized by dry summers and cold, wet winters. Herbivory has historically occurred on this site at low levels of utilization. Herbivores include mule deer, whitetail deer, Rocky Mountain elk, lagomorphs, and small rodents.
Fire has historically occurred on the site at intervals of 25-40 years.
The Reference State (State 1), moves through many phases depending on the natural and man-made forces that impact the community over time. State 1, described later, indicates some of these phases. The Reference Plant Community Phase is Phase A. This plant community is dominated by bluebunch wheatgrass and Sandberg bluegrass in the understory. Subdominant species include sand dropseed, Fendler threeawn, lupine, aster, and milkvetch. The plant species composition of Phase A is listed later under “Reference Plant Community Phase Plant Species Composition”.
Total annual production is 1000 pounds per acre (1120 kilograms per hectare) in a normal year. Production in a favorable year is 1200 pounds per acre (1344 kilograms per hectare). Production in an unfavorable year is 800 pounds per acre (896 kilograms per hectare). Structurally, cool season, deep rooted perennial grasses are dominant followed by perennial forbs while shallow rooted bunchgrasses are subdominant.
This site is suitable for late spring, summer, and fall grazing. The steeper slopes will limit livestock movement. Excessive trailing of livestock should be avoided to minimize terracette development and erosion on the steeper slopes. This site provides valuable wildlife food and cover for deer, elk, raptors and other small wildlife species.
The soils in this group are in hydrologic group D.
This site has slight recreational or aesthetic value.
Impacts on the Plant Community:
Influence of fire:
When this site burns within the normal fire frequency of 25-40 years, it has minimal effect on the plant community.
In the absence of normal fire frequency residues will build up in the crown of bluebunch wheatgrass. Plant decadence develops. When fires become more frequent than historic levels (25-40 years), vigor of the bunchgrasses will generally be reduced for a year or two. Root sprouting shrubs such as green rabbitbrush will increase. With continued short fire frequency, fine leaved grasses will have their vigor reduced significantly and death may result. These species may be replaced by Fendler threeawn, cheatgrass, Sandberg bluegrass, ventenata, and bulbous bluegrass along with a variety of annual and perennial forbs including noxious and invasive plants.
Influence of improper grazing management:
Season-long grazing and/or excessive utilization can be very detrimental to this site. This type of management leads to reduced vigor of the bunchgrasses. With reduced vigor, recruitment of these species declines. As these species decline, the plant community becomes susceptible to invasion by noxious and invasive plants.
Continued improper grazing management influences fire frequency by increasing fine fuels.
Proper grazing management that addresses frequency, duration, and intensity of grazing can also keep fine fuels from developing, thereby reducing fire frequency. A planned grazing system can be developed to intentionally accumulate fine fuels in preparation for a prescribed burn. Prescribed burns need careful planning. Areas without a suitable understory of perennial grasses are low priority areas for prescribed burns, especially if reseeding is not a possibility.
Due to the unstable soil surface, improper grazing management usually results in the development of terracettes. On steeper slopes massive soil erosion can occur during intense convection storms.
Weather influences:
Above normal precipitation in March, April, and May can dramatically increase total annual production of the plant community. These weather patterns can also increase viable seed production of desirable species to provide for recruitment. Likewise, below normal precipitation during these spring months can significantly reduce total annual production and be detrimental to viable seed production. Overall plant composition is normally not affected when perennials have good vigor.
Below normal temperatures in the spring can have an adverse impact on total production regardless of the precipitation. An early, hard freeze can occasionally kill some plants.
Prolonged drought adversely affects this plant community in several ways. Vigor, recruitment, and production are usually reduced. Mortality can occur, especially in shallow rooted species. Prolonged drought can lead to a reduction in fire frequency.
Influence of Insects and disease:
Insect and disease outbreaks can affect vegetation health. Mormon cricket and grasshopper outbreaks occur periodically. Since defoliation usually happens once during the growing season, mortality is normally low.
An outbreak of a particular insect is usually influenced by weather but no specific data for this site is available.
Influence of noxious and invasive plants:
Many of these species add to the fine-fuel component and lead to increased fire frequency. Many of the annual and perennial invasive species with deep root systems compete with desirable plants for moisture and nutrients. The result is reduced production and change in composition of the understory.
Influence of wildlife:
Big game animals use this site in the spring, summer, and fall. Their numbers are seldom high enough to adversely affect the plant community.
Watershed:
Decreased infiltration and increased runoff occur with an increase in annual grasses and undesirable forbs. Desired understory species can be reduced. This composition change can affect nutrient and water cycles. Increased runoff also causes sheet and rill erosion. Abnormally short fire frequency also gives the same results, but to a lesser degree. The long term effect is a transition to a different state.
Plant Community and Sequence:
Transition pathways between common vegetation states and phases:
State 1.
Phase A to B. Develops with improper grazing management and no fire.
Phase A to C. Develops with fire.
Phase B to A. Develops with prescribed grazing.
Phase C to A. Develops with prescribed grazing and no fire.
State 1 Phase B to State 2. Develops through frequent fire and continued improper grazing management. The site crosses the threshold. It is not economically feasible to move this state back to State 1 with accelerating practices.
State 1 Phase C to State 2. Develops through frequent fire or continued improper grazing management. The site crosses the threshold. It is not economically feasible to move this state back to State 1 with accelerating practices.
State 2 to unknown site. Excessive soil loss and changes in the hydrologic cycle caused by continued improper grazing management and/or frequent fire cause this state to cross a threshold and retrogress to a new site with reduced potential. It is not economically feasible to move this state back to State 1 with accelerating practices.
Practice Limitations.
There are moderate to severe limitations for seeding on this site by conventional methods due to steep slopes. Attaining uniform utilization on the steeper slopes is difficult.State and transition model
Custom diagramStandard diagram
More interactive model formats are also available. View Interactive Models
More interactive model formats are also available. View Interactive Models
Click on state and transition labels to scroll to the respective textState 1 submodel, plant communities
State 2 submodel, plant communities
State 3 submodel, plant communities
State 4 submodel, plant communities
State 5 submodel, plant communities
State 1
State 1 Phase ACommunity 1.1
State 1 Phase AState 1, Phase A. Reference Plant Community Phase. This plant community is dominated by bluebunch wheatgrass and Sandberg bluegrass. Subdominant species include sand dropseed, Fendler threeawn, lupine, aster, and milkvetch. Natural fire frequency is 25-40 years.
Figure 3. Annual production by plant type (representative values) or group (midpoint values)
Table 5. Annual production by plant type
Plant type Low
(lb/acre)Representative value
(lb/acre)High
(lb/acre)Grass/Grasslike 625 780 935 Forb 160 200 240 Shrub/Vine 15 20 25 Total 800 1000 1200 Figure 4. Plant community growth curve (percent production by month). ID0101 , B9 PSSPS-FEID REFERENC PLANT COMMUNITY. State 1.
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 5 20 35 25 10 0 0 5 0 0 State 2
State 1 Phase BCommunity 2.1
State 1 Phase BState 1, Phase B. This plant community is dominated by Sandberg bluegrass with reduced amounts of bluebunch wheatgrass. All deep-rooted bunchgrasses are typically in low vigor. Fendler threeawn has increased. This state has developed due to improper grazing management and no fire. Some cheatgrass and other invasive annuals may have invaded the site.
Figure 5. Plant community growth curve (percent production by month). ID0101 , B9 PSSPS-FEID REFERENC PLANT COMMUNITY. State 1.
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 5 20 35 25 10 0 0 5 0 0 State 3
State 1 Phase CCommunity 3.1
State 1 Phase CState 1, Phase C. This plant community is dominated by bluebunch wheatgrass and Sandberg bluegrass . Bluebunch wheatgrass has reduced vigor. Forbs remain about in the same proportion as Phase A. Green rabbitbrush has resprouted from fire. Some cheatgrass may have invaded the site. This plant community is the result of wildfire.
Figure 6. Plant community growth curve (percent production by month). ID0101 , B9 PSSPS-FEID REFERENC PLANT COMMUNITY. State 1.
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 5 20 35 25 10 0 0 5 0 0 State 4
State 2Community 4.1
State 2State 2. This plant community is dominated by cheatgrass and other annuals. Root sprouting shrubs such as green rabbitbrush can be present, dependent upon, how frequent fire, has occurred. Some soil loss has occurred. This state has developed due to frequent fires and improper grazing management from Phase B, State 1. It also develops with frequent fire or improper grazing management from Phase C, State 1. The site has crossed the threshold. It is not economically feasible to move this state back to State 1 with accelerating practices.
Figure 7. Plant community growth curve (percent production by month). ID0102 , B9 BRTE-ANNUALS. State 2.
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 10 30 40 15 0 0 0 5 0 0 State 5
State 3Community 5.1
State 3Additional community tables
Table 6. Community 1.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Grass/Grasslike1 Grass and Grasslike – bluebunch wheatgrass PSSPS Pseudoroegneria spicata ssp. spicata 520–780 – Sandberg bluegrass POSE Poa secunda 50–70 – sand dropseed SPCR Sporobolus cryptandrus 25–35 – Fendler threeawn ARPUL Aristida purpurea var. longiseta 15–25 – Forb2 Forbs – lupine LUPIN Lupinus 35–55 – aster ASTER Aster 30–50 – milkvetch ASTRA Astragalus 30–50 – cous biscuitroot LOCO4 Lomatium cous 30–40 – goldenrod SOLID Solidago 25–35 – common yarrow ACMI2 Achillea millefolium 25–35 – pale agoseris AGGL Agoseris glauca 25–35 – sego lily CANU3 Calochortus nuttallii 15–25 – Shrub/Vine3 Shrubs – yellow rabbitbrush CHVI8 Chrysothamnus viscidiflorus 1–10 – spiny greasebush GLSPA Glossopetalon spinescens var. aridum 1–10 – Table 7. Community 2.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 8. Community 3.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 9. Community 4.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Table 10. Community 5.1 plant community composition
Group Common name Symbol Scientific name Annual production () Foliar cover (%) Interpretations
Animal community
Wildlife Interpretations.
This site provides valuable wildlife food and cover for deer, elk, raptors, and other small wildlife species.
Grazing Interpretations.
This site is suitable for late spring, summer, and fall grazing. The steeper slopes will limit livestock movement. Excessive trailing of livestock should be avoided to minimize terracette development and erosion on the steeper slopes.
Estimated Initial Stocking Rate.
Estimated initial stocking rate will be determined with the landowner or decision-maker. They will be based on the inventory which includes species, composition, similarity index, production, past use history, season of use, and seasonal preference. Calculations used to determine estimated initial stocking rate will be based on forage preference ratings.
Hydrological functions
The soils in this group are in hydrologic group D.
Recreational uses
This site has slight recreational or aesthetic value.
Wood products
None.
Other products
None.
Other information
Field Offices
Grangeville, ID
Lewiston, ID
Craigmont, ID
Orofino, ID
St. Maries, ID
Coeur d’Alene, ID
Supporting information
Inventory data references
Information presented here has been derived from NRCS clipping and other inventory data. Also, field knowledge of range-trained personnel was used. Those involved in developing this site description include: Dave Franzen, co-owner, Intermountain Rangeland Consultants, LLC Jacy Gibbs, co-owner, Intermountain Rangeland Consultants, LLC Jim Cornwell, Range Management Specialist, IASCD Brendan Brazee, State Rangeland Management Specialist, NRCS, Idaho Bruce Knapp, Resource Soil Scientist, NRCS, Idaho Lee Brooks, Range Management Specialist, IASCD
Type locality
Location 1: Idaho County, ID General legal description Steep west facing slope back of Lucille Bar on Salmon River. Other references
Hironaka, M., M.A. Fosberg, A. H. Winward. 1983. Sagebrush-Grass Habitat Types of Southern Idaho. University of Idaho. Moscow, Idaho. Bulletin Number “35”.
USDA Forest Service, Rocky Mountain Research Station. 2004. Restoring Western Ranges and Wildlands. General Technical Report RMRS-GTR-136-vols. 1-3.
USDA, NRCS.2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov.). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.
USDA, Forest Service, Fire Effects Information Database. 2004. www.fs.fed.us/database.
USDI Bureau of land Management, US Geological Survey; USDA Natural Resources Conservation Service, Agricultural Research Service; Interpreting Indicators of Rangeland Health. Technical Reference 1734-6; Version 4-2005.
Approval
Kendra Moseley, 9/23/2020
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) Dave Franzen and Jacy Gibbs Intermountain Range Consultants 17700 Fargo Rd. Wilder, ID 83676 Contact for lead author Brendan Brazee, State Rangeland Management Specialist USDA-NRCS 9173 W. Barnes Drive, Suite C, Boise, ID 83709 Date 04/15/2009 Approved by Approval date Composition (Indicators 10 and 12) based on Annual Production Indicators
-
Number and extent of rills:
Rills are rare on this site. If rills are present they are likely to occur on the steeper slopes and immediately following wildfire. Coarse surface stones and gravels limit rill development. -
Presence of water flow patterns:
Water-flow patterns are rare on this site. When they occur they are short and disrupted by cool season grasses and surface stones and are not extensive. -
Number and height of erosional pedestals or terracettes:
Pedestals are rare on this site. Terracettes are common. Significant accumulation of coarse surface fragments develops on the uphill side of larger perennial grasses. This accumulation is from concentrated flow and hoof/ foot traffic. Terracettes are a natural occurrence on the site. -
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Ranges from 40-50%. This site is naturally unstable due to coarse surface fragments. -
Number of gullies and erosion associated with gullies:
None. -
Extent of wind scoured, blowouts and/or depositional areas:
Usually not present due to coarse textured, gravelly soil surface. -
Amount of litter movement (describe size and distance expected to travel):
Fine litter in the interspaces may move up to 3 feet following a significant run-off event. It generally moves onto terracettes. Coarse litter generally does not move except on the steeper slopes. Litter is also moved mechanically by hoof/ foot traffic. -
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Values should range from 4 to 6 but needs to be tested. -
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
The surface horizon is typically 2 to 4 inches thick. Structure ranges from weak fine platy to weak fine or very fine granular. Soil organic matter (SOM) ranges from 2 to 4 percent. -
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Bunchgrasses, especially deep-rooted perennials, slow run-off and increase infiltration. -
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
Is not present. -
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:
cool season deep-rooted perennial bunchgrassesSub-dominant:
perennial forbsOther:
shallow rooted bunchgrassesAdditional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Plant decadence can occur on this site in the absence of grazing and/or fire. Mortality can occur following extended drought. Some grasses and forbs are susceptible to hoof/ foot traffic. -
Average percent litter cover (%) and depth ( in):
Additional litter cover data is needed but is expected to be 5-10 percent to a depth of <0.1 inches. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
Is 1000 pounds per acre (1120 kilograms per hectare) in a year with normal temperatures and precipitation. Perennial grasses produce 75-85 percent of the total production, forbs 15-25 percent, and shrubs T-3 percent. -
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:
Includes cheatgrass, soft chess, ventenata, bulbous bluegrass, medusahead, tarweed, curlycup gumweed, dalmation toadflax, spotted and diffuse knapweed, and yellow starthistle. -
Perennial plant reproductive capability:
All functional groups have the potential to reproduce in most years.
Print Options
Sections
Font
AAAAOther
PrintThe Ecosystem Dynamics Interpretive Tool is an information system framework developed by the USDA-ARS Jornada Experimental Range, USDA Natural Resources Conservation Service, and New Mexico State University.
Accessibility statement
