Natural Resources
Conservation Service
Ecological site R030XC028NV
ALPINE SLOPE
Last updated: 2/25/2025
Accessed: 03/17/2025
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.
Classification relationships
Nachlinger, J. and G. Reese. 1996. Plant Community Classification of the Spring mountains National Recreation Area, Clark and Nye Counties, Nevada. The Nature Conservancy. Reno, Nevada. III. High conifer forest and Woodland Zone. 11 Ivesia cryptocaulis Series. Hidden ivesia Series. Page I-73-74.
Ecological site concept
This site occurs on high wind-swept mountain ridges, and upper back slopes of mountains on all aspects. This site is associated with relatively unstable talus slopes or scree. Slopes range from 4 to 50 percent. Elevations range from 10,000 to 11,900 feet. The soils associated with this site are shallow to moderately deep, well drained soils that formed in colluvium and residuum from limestone and dolomite.
This is a group concept and provisional STM that also covers R030XC002NV, R030XC019NV, R030XC026NV, R030XC029NV
Associated sites
| F030XC284NV |
Pinus longaeva-Pinus flexilis/Juniperus communis var. depressa/Carex rossii This site occurs at lower elevations. |
|---|---|
| F030XC285NV |
Pinus longaeva/Salvia dorrii ssp. dorrii var. clokeyi-Ribes montigenum/Achnatherum lettermanii-Carex rossii This site occurs at lower elevations. |
| R030XC029NV |
SNOWPOCKET This site occurs at lower elevations in areas of snow accumulation. Higher grass production. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
Not specified |
| Herbaceous |
(1) Ivesia cryptocaulis |
Physiographic features
This site occurs on high wind-swept mountain ridges, and upper back slopes of mountains on all aspects. This site is associated with relatively unstable talus slopes or scree. Slopes range from 4 to 50 percent. Elevations range from 10,000 to 11,900 feet.
Table 2. Representative physiographic features
| Landforms |
(1)
Mountain
(2) Mountain slope (3) Ridge |
|---|---|
| Elevation | 3,048 – 3,627 m |
| Slope | 4 – 50% |
Climatic features
The primary air masses affecting the Spring Mountains are cold maritime polar air from the Gulf of Alaska and warmer, moist maritime subtropical air from lower latitudes. Occasionally there are invasions of cold continental polar air from northern Canada or the Rocky Mountains. Precipitation in the area results primarily from the passage of cyclones with associated fronts during fall, winter and spring; from closed cyclones in late winter and spring; and from the flow of moist tropical air from the southeast to the southwest quadrant in the summer.
The characteristic climate is alpine tundra, with cool summers and cold winters. Intense winds over this site inhibit snow accumulation and thus lower the effective precipitation. The mean annual precipitation is 18 to 24 inches. Mean annual air temperature is 37 to 41 degrees F. The average growing season is about 40 to 60 days.
Table 3. Representative climatic features
| Frost-free period (average) | 60 days |
|---|---|
| Freeze-free period (average) | |
| Precipitation total (average) | 610 mm |
Influencing water features
There are no influencing water features associated with this site.
Soil features
The soils associated with this site are shallow to moderately deep, well drained soils that formed in colluvium and residuum from limestone and dolomite. These soils have high amounts of gravels, cobbles, or stones on the surface which occupy plant growing space yet protect the soil from excessive erosion. The available water capacity is very low, but the surface cover of rock fragments helps to reduce evaporation and conserve soil moisture. The soil temperature regime is cryic and the soil moisture regime is udic. The soils has an ochric epipedon and calcic horizon. Soil series associated with this site include Charpeak.
Table 4. Representative soil features
| Surface texture |
(1) Extremely gravelly fine sandy loam (2) Extremely gravelly sandy loam |
|---|---|
| Family particle size |
(1) Loamy |
| Drainage class | Well drained |
| Permeability class | Moderately rapid |
| Soil depth | 10 – 99 cm |
| Surface fragment cover <=3" | 65 – 90% |
| Surface fragment cover >3" | 0 – 5% |
| Available water capacity (0-101.6cm) |
0.76 – 3.05 cm |
| Calcium carbonate equivalent (0-101.6cm) |
5 – 25% |
| Electrical conductivity (0-101.6cm) |
0 – 2 mmhos/cm |
| Sodium adsorption ratio (0-101.6cm) |
0 |
| Soil reaction (1:1 water) (0-101.6cm) |
7.9 – 8.4 |
| Subsurface fragment volume <=3" (Depth not specified) |
70 – 80% |
| Subsurface fragment volume >3" (Depth not specified) |
1 – 3% |
Ecological dynamics
Plant community composition varies with differences in aspect, size, and amount of rock fragments on the surface, and steepness of slope. Areas of snow accumulation, mostly on north facing slopes, tend to be dominated by herbaceous species. Alpine communities are sensitive to disturbance and the effects of human disturbances are more drastic and long-lasting than in other plant communities. Vegetation recovery is slow because of the cold and extreme temperatures, high winds, prolonged snow cover, and intense ultraviolet radiation. Fire occurs very infrequently in alpine communities and fire size is small, sometimes limited to a single tree.
Cheatgrass has spread to high elevations in the western U.S. over the last 10 to 15 years. This range expansion may due to 1) local adaptation, 2)phenotypic plasticity of all-purpose genotypes, 3) changes in climate, 4) increased local disturbance, 5) nutrient enrichment and 6) seed dispersal, or some combination of one or more of these mechanisms.
State and transition model
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Ecosystem states
State 1 submodel, plant communities
State 1
Reference Plant Community
Community 1.1
Reference Plant Community
The reference plant community is composed of low-growing perennial grasses and forbs. Common grasses include alpine fescue, bluegrasses, and bottlebrush squirreltail. Low-statured bristlecone pine trees line the lower margin of this plant community as a stunted krummholz shrub. Potential vegetative composition is approximately 35 percent grasses and grass-like plants, 55 percent forbs and 10 percent shrubs and low-statured trees. Approximate ground cover (basal and canopy)is approximately 10 to 20 percent. Total annual air-dry production is 75 pounds for favorable years, 25 pounds for normal years and 15 pounds for unfavorable years.
Figure 1. 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) |
|---|---|---|---|
| Forb | 46 | 77 | 93 |
| Grass/Grasslike | 29 | 48 | 58 |
| Shrub/Vine | 4 | 8 | 9 |
| Tree | 4 | 7 | 8 |
| Total | 83 | 140 | 168 |
Table 6. Ground cover
| Tree foliar cover | 0-5% |
|---|---|
| Shrub/vine/liana foliar cover | 0-2% |
| Grass/grasslike foliar cover | 2-4% |
| Forb foliar cover | 4-7% |
| Non-vascular plants | 1-2% |
| Biological crusts | 1-5% |
| Litter | 0-1% |
| Surface fragments >0.25" and <=3" | 65-90% |
| Surface fragments >3" | 1-10% |
| Bedrock | 1-10% |
| Water | 0% |
| Bare ground | 10-35% |
Table 7. Canopy structure (% cover)
| Height Above Ground (m) | Tree | Shrub/Vine | Grass/ Grasslike |
Forb |
|---|---|---|---|---|
| <0.15 | 0% | 0-1% | 1-2% | 1-2% |
| >0.15 <= 0.3 | 0-1% | 1-2% | 1-2% | 2-5% |
| >0.3 <= 0.6 | 0-3% | 1-2% | – | – |
| >0.6 <= 1.4 | 0-3% | – | – | – |
| >1.4 <= 4 | – | – | – | – |
| >4 <= 12 | – | – | – | – |
| >12 <= 24 | – | – | – | – |
| >24 <= 37 | – | – | – | – |
| >37 | – | – | – | – |
State 2
Annual Invasive Species
Annual cool season grasses such as cheatgrass have gained a foothold on the site.
Transition T1A
State 1 to 2
Invasion of annual cheatgrass. Once invaded it is unlikely that the site can once regain reference.
Additional community tables
Table 8. Community 1.1 plant community composition
| Group | Common name | Symbol | Scientific name | Annual production (kg/hectare) | Foliar cover (%) | |
|---|---|---|---|---|---|---|
|
Grass/Grasslike
|
||||||
| 1 | Primary Perennial Grasses | 13–35 | ||||
| alpine fescue | FEBR | Festuca brachyphylla | 13–35 | – | ||
| spiny milkvetch | ASKEJ | Astragalus kentrophyta var. jessiae | 0–17 | – | ||
| Charleston Peak mousetail | IVCR | Ivesia cryptocaulis | 0–17 | – | ||
| mountain oxytrope | OXOR2 | Oxytropis oreophila | 0–11 | – | ||
| elegant cinquefoil | POCO13 | Potentilla concinna | 0–11 | – | ||
| Hitchcock's bladderpod | LEHI3 | Lesquerella hitchcockii | 0–6 | – | ||
| whitespine thistle | CICL2 | Cirsium clokeyi | 0–6 | – | ||
| Charleston Mountain pussytoes | ANSO2 | Antennaria soliceps | 0–6 | – | ||
| Utah columbine | AQSC | Aquilegia scopulorum | 0–6 | – | ||
| compact chickensage | SPCO8 | Sphaeromeria compacta | 0–6 | – | ||
| Charleston Mountain kittentails | SYRA2 | Synthyris ranunculina | 0–6 | – | ||
| Clokey's fleabane | ERCL | Erigeron clokeyi | 0–6 | – | ||
| Jaeger's draba | DRJA | Draba jaegeri | 0–2 | – | ||
| Clokey's catchfly | SICL | Silene clokeyi | 0–1 | – | ||
| 2 | Secondary Perennial Grasses | 1–13 | ||||
| Ross' sedge | CARO5 | Carex rossii | 1–4 | – | ||
| squirreltail | ELEL5 | Elymus elymoides | 1–4 | – | ||
| Sandberg bluegrass | POSE | Poa secunda | 1–4 | – | ||
| whitespine thistle | CICL2 | Cirsium clokeyi | 0–1 | – | ||
|
Forb
|
||||||
| 3 | Primary Perennial Forbs | 35–63 | ||||
| Charleston Peak mousetail | IVCR | Ivesia cryptocaulis | 21–35 | – | ||
| Utah columbine | AQSC | Aquilegia scopulorum | 13–28 | – | ||
| 4 | Secondary Perennial Forbs | 13–28 | ||||
| broadkeel milkvetch | ASPL3 | Astragalus platytropis | 1–4 | – | ||
| whitespine thistle | CICL2 | Cirsium clokeyi | 1–4 | – | ||
| Jaeger's draba | DRJA | Draba jaegeri | 1–4 | – | ||
| Clokey's fleabane | ERCL | Erigeron clokeyi | 1–4 | – | ||
| Hitchcock's bladderpod | LEHI3 | Lesquerella hitchcockii | 1–4 | – | ||
| mountain oxytrope | OXORO | Oxytropis oreophila var. oreophila | 1–4 | – | ||
| elegant cinquefoil | POCO13 | Potentilla concinna | 1–4 | – | ||
| Clokey's catchfly | SICL | Silene clokeyi | 1–4 | – | ||
| compact chickensage | SPCO8 | Sphaeromeria compacta | 1–4 | – | ||
| Charleston Mountain kittentails | SYRA2 | Synthyris ranunculina | 1–4 | – | ||
|
Shrub/Vine
|
||||||
| 5 | Secondary Shrubs | 1–22 | ||||
| common juniper | JUCOD | Juniperus communis var. depressa | 1–11 | – | ||
| gooseberry currant | RIMO2 | Ribes montigenum | 1–11 | – | ||
|
Tree
|
||||||
| 6 | Trees | 1–11 | ||||
| Great Basin bristlecone pine | PILO | Pinus longaeva | 1–11 | – | ||
Interpretations
Animal community
Livestock Interpretations:
This site has limited value for livestock grazing due to low forage production and lack of stock water.
Wildlife Interpretations:
Bighorn sheep may utilize this site during the summer. Various songbirds, rodents, and associated predators native to the area may be found.
Hydrological functions
Rills – Common on steep slopes.
Water Flow Patterns – Common on steep slopes from rain and snowmelt.
Terracettes – Common on steep slopes.
Gullies – Not common.
Recreational uses
This site is used primarily for recreational activities, such as hiking, bird watching, and camping.
Other information
There are 9 plant species of concern associated with this ecological site at the Spring Mountain National Recreational Area (SMNRA). Eight species are endemic to the SMNRA. There is one butterfly species of concern associated with this ecological site which is endemic to the SMNRA.
Supporting information
Type locality
| Location 1: Clark County, NV | |
|---|---|
| Township/Range/Section | T19 S R56 E S28 |
| UTM zone | N |
| UTM northing | 4014195n |
| UTM easting | 0617219e |
| General legal description | Approximately 0.25 miles southeast of Charleston Peak, Spring Mountains, Clark County, Nevada. |
Other references
Browne, C.S. (no date). The unwelcome arrival of Bromus tectorum to high elevations. Department of Bioagricultural Sciences and Pest Management. Colorado State University, Fort Collins.
Clokey, I. 1951. Flora of the Charleston Mountains, Clark County, Nevada. University of California Press, Berkeley and Los Angeles.
Fire Effects Information System [Online]http://www.fs.fed.us/feis
Glenne, G., and D. Johnson. 2002. Guide to Species of Concern in the Spring Mountains National Recreation Area, Clark and Nye Counties, Nevada. USFS, Las Vegas, NV.
Lanner, R.M. 1984. Trees of the Great Basin. University of Nevada Press, Reno NV.
Nachlinger, J. and G. Reese. 1996. Plant Community Classification of the Spring mountains National Recreation Area, Clark and Nye Counties, Nevada. The Nature Conservancy. Reno, Nevada. III. High conifer forest and Woodland Zone. 11 Ivesia cryptocaulis Series. Hidden ivesia Series. Page I-73-74.
Contributors
TJWolfe
Approval
Sarah Quistberg, 2/25/2025
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) | TJ Wolfe |
|---|---|
| Contact for lead author | State Rangeland Management Specialist |
| Date | 11/17/2005 |
| Approved by | Sarah Quistberg |
| Approval date | |
| Composition (Indicators 10 and 12) based on | Annual Production |
Indicators
-
Number and extent of rills:
Common on steep slopes.
-
Presence of water flow patterns:
Common on steep slopes from rain and snowmelt.
-
Number and height of erosional pedestals or terracettes:
Terracettes are common on steep slopes.
-
Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):
Bare ground is approximately 1 to 10 percent. Mostly covered by rock.
-
Number of gullies and erosion associated with gullies:
None
-
Extent of wind scoured, blowouts and/or depositional areas:
None
-
Amount of litter movement (describe size and distance expected to travel):
Fine litter (1 inch or less in size) moves short distances with water or wind.
-
Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):
Soil surface is very resistant to erosion because of the high amounts of rock fragments on the surface. Stability values 3-5 (needs field testing).
-
Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):
Surface structure is typically moderate, fine subangular blocky. Soil surface colors are light and the soils are typified with an ochric epipedon. Organic matter is 0.25 to 0.75 percent.
-
Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:
Plant community composition is approximately 90 percent herbaceous production with 10 to 20 percent ground cover. Soils have moderately rapid permeability. Tap-rooted perennial forbs and deep-rooted perennial bunchgrasses slow runoff and increase infiltration.
-
Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):
None - a calcic horizon occurs from 2 to 29 inches. -
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:
Perennial forbs > Deep-rooted, cool-season perennial bunchgrasses >Sub-dominant:
associated shrubs > evergreen treesOther:
Additional:
-
Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):
Evergreen trees will show some (<20%) decadence. -
Average percent litter cover (%) and depth ( in):
Litter cover is approximately 1 percent and less than 0.25 inches in depth. -
Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):
For normal or average growing season, approximately 125 lbs/ac. -
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:
Cheatgrass -
Perennial plant reproductive capability:
All functional groups should reproduce in average (or normal) and above average growing season years.
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