Physiographic features

This site occurs on moderately steep to steep mountain tops and mountain slopes. Slopes range from 2 to 30 percent, occasionally up to 60, on all aspects. Elevations range from 7000 to 9500 feet (2100 to 2900 meters).

Table 2. Representative physiographic features

Climatic features

MLRA 13, the Eastern Idaho Plateaus, is part of the Northwestern Wheat and Range Region. Its elevation ranges from 4209 to 9331 feet above sea level, with an average elevation of 5787 feet. The average annual precipitation is 16.41 inches, with a range of 13.56 to 18.75 inches, based on ten long term climate stations located throughout the MLRA. A spike in precipitation amount often occurs in late spring, usually in May.
Temperatures vary widely in the MLRA throughout the year. A maximum temperature of 103° Fahrenheit occurred at the McCammon climate station (# 105716; elevation 4770 feet), while a minimum of -41° was recorded at the Kilgore station (#104908). At all stations temperatures throughout the year are usually below the national average. Kilgore also recorded the greatest annual snowfall amount of 217 inches. The average temperature is 41.4 degrees F. with an average high of 55.3 degrees and an average low of 27.5 degrees.
The frost-free period ranges from 64 to 90 days, while the freeze-free period can be 98 to 123 days.

Table 3. Representative climatic features

Influencing water features

This site is not influenced by adjacent wetlands, streams, or run on.

Soil features

These soils are moderately deep to very deep well drained gravelly to very stony silt loams with very cobbly and extremely cobbly subsoil. They formed in residuum, alluvium, and colluvium derived from sedimentary and metasedimentary rock dominated by quartzite. Coarse fragments exist in the soil profile and increase with depth, usually exceeding 35 percent by volume and in some cases exceeding 60 percent. Permeability is moderate and runoff is high. The available water holding capacity (AWC) is very low to low. The site is characterized by a xeric soil moisture regime and a cryic soil temperature regime.



Soil Series Correlated to this Ecological Site

Camelback variant Valmar variant

Table 4. Representative soil features

Animal community

Wildlife Interpretations.

Animal Community – Wildlife Interpretations

This rangeland ecological site provides diverse habitat for many native wildlife species. The plant community exhibits a diverse mixture of forbs throughout the growing season offering excellent habitat for invertebrates. Mule deer, moose, and elk may utilize the site at different times of the year. The rangeland provides seasonal habitat for resident and migratory animals including western toad, shrews, bats, ground squirrels, mice, coyote, red fox, badger, Ferruginous hawk, and prairie falcon. Area sensitive bird species include Brewer’s sparrow, sage thrasher, sage sparrow, and sage-grouse. Water features are sparse provided by seasonal runoff, artificial water catchments, and springs.

State 1 Phase 1.1 –Subalpine Big Sagebrush/ Slender Wheatgrass/ Mountain Brome Reference Plant Community (RPC): This plant community provides a diversity of grasses, forbs, and shrubs used by native insect communities that assist in pollination. An extensive array of forbs is represented throughout the growing season leading to a diverse insect community. Many avian and mammal species utilize this habitat based on the availability of invertebrate prey species. The reptile and amphibian community is represented by common sagebrush lizard, western toad, and northern leopard frog. Amphibians are associated with springs and isolated water bodies adjacent to this plant community. Development of spring sites that collect all available water would exclude amphibian use on these sites. Native shrub-steppe obligate avian species utilizing the habitat include the Brewer’s sparrow, sage sparrow, sage grouse, and sage thrasher. Sage-grouse habitat (brood-rearing and winter) is provided by this plant community. The plant community provides seasonal food and cover for large mammals including mule deer, moose, and elk. Slender wheatgrass and mountain brome are important forage species for these large mammals during spring and fall. Subalpine big sagebrush provides big game forage throughout the year. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, Great Basin Kangaroo rat, and chipmunks utilize this plant community. Pikas may utilize the site if adjacent to talus slopes at higher elevations.


State 1 Phase 1.2- Subalpine Big Sagebrush/ Slender Wheatgrass/ Mountain Brome/ Rocky Mountain Juniper Plant Community: This plant community is the result of improper grazing management and fire return intervals being much longer than normal. An increase in canopy cover of sagebrush and juniper contributes to a sparse herbaceous understory. A reduced herbaceous understory results in lower diversity and numbers of insects. The reptile community will be similar to the State 1 Phase 1.1. The reduced diversity of insects and understory cover may reduce the quality of food and cover for reptiles. As juniper increases, quality of habitat for Brewer’s sparrow, sage thrasher, and sage sparrow may increase. Remaining sagebrush provides brood-rearing, winter cover, and winter food habitat for sage-grouse but as juniper encroachment increases the quality of this habitat is severely reduced or eliminated. The plant community supports spring through fall habitat for mule deer, elk, and moose. As juniper encroaches, the site will provide additional thermal cover for large mammals. Winter habitat quality for mule deer may increase with the addition of juniper to the plant community. A small mammal population similar to that in State 1 Phase 1.1 is present, including golden-mantled ground squirrels, jackrabbits, deer mice, Great Basin Kangaroo rat, and pikas (when talus slopes are adjacent to site).

State 1 Phase 1.3 – Slender Wheatgrass/ Mountain Brome/ Spike Fescue/ Root Sprouting Shrubs Plant Community: This plant community is a result of recent wildfire or prescribed burning. The plant community, dominated by herbaceous vegetation with little or no sagebrush would provide less vertical structure for animals. Patches of root sprouting shrubs (mountain snowberry) may be present to provide limited vertical structure. Insect diversity would be reduced, but a native forb plant community similar to that in State 1 Phase 1.1 would still support select pollinators. Reptiles including common sagebrush lizard would be limited due to the loss of sagebrush. Amphibian habitat would be tied to permanent spring sites in the area. Development of spring sites that collect all available water would exclude the use of amphibians on these sites. The dominance of herbaceous vegetation with patches of mountain snowberry would limit or exclude nesting by Brewer’s sparrow, sage sparrow, sage grouse, and sage thrasher. The herbaceous vegetation improves habitat for grassland avian species (horned lark, savannah sparrow, vesper sparrow, and western meadowlark). Mule deer and elk use would be seasonal but the site would offer little young of year cover due to the loss of shrubs. The populations of small mammals would be dominated by species that prefer grass seed and open habitat. Large blocks of this plant community would fragment the reference plant community and severely reduce the quality of the habitat for shrub-steppe obligate animal species.

State 1 Phase 1.4 – Subalpine Big Sagebrush/ Slender Wheatgrass/ Mountain Brome Plant Community: This plant community is the result of improper grazing management and no fire. An increase in canopy cover of sagebrush contributes to a sparse herbaceous understory. The reduced herbaceous understory results in lower diversity of insects. The reptile community would be similar to the State 1Phase 1.1 animal community. The reduced diversity of insects may reduce reptile diversity and populations. Shrub-steppe obligate bird species include Brewer’s sparrow, sage sparrow, sage thrasher, and sage-grouse. Quality of brood-rearing habitat for sage-grouse is reduced due to a less diverse herbaceous plant community. Winter habitat (cover and food) for sage-grouse is provided. The reduced vigor of understory vegetation provides a shorter forage season for mule deer and elk. Young of year cover would be provided for mule-deer. Small mammal populations would be similar to those in State 1Phase 1.1
State 2 – Annuals Plant Community:
This state has developed due to continued improper grazing management and frequent fire. The plant community does not support a diverse insect community. The lack of native forbs and shrubs in the plant community would support a very limited population of pollinators. Most reptilian species are not supported with food, water, or cover. This plant community does not support the habitat requirements for sage thrasher, Brewer’s sparrow, sage-grouse, or sage sparrow. Diversity of grassland avian species is reduced due to poor cover and available food. Birds of prey including hawks and falcons may range throughout these areas looking for prey species. Large mammals may utilize the herbaceous vegetation in the early part of the year when the invasive annuals (cheatgrass) are more palatable. The populations of small mammals would be dominated by open grassland species. Large blocks of this plant community would fragment the reference plant community and reduce the quality of the habitat for shrub-steppe obligate animal species.

State 3 - Rocky Mountain Juniper / Annuals Plant Community: This state has developed due to improper grazing management and no fire. The loss of native understory vegetation will reduce insect diversity on the site. The lack of flowering plants reduces use by pollinator use by butterflies and moths. Quality of habitat for reptilian species identified in State 1 Phase 1.1 is reduced. This plant community does not support the habitat requirements for sage-grouse. Birds using this site as resident or migratory habitat include Juniper titmouse, western bluebird, and Virginia’s warbler. The Juniper titmouse relies heavily on juniper seeds for winter food. Hunting success by raptors may decrease due to a heavy overstory of juniper. Hunting success by raptors on adjacent ecological sites may increase due to roosting and perch sites provided by juniper. The plant community supports limited seasonal habitat for elk and moose in spring and fall. The quality of winter habitat for mule deer may increase. As juniper encroaches, the site will provide additional thermal cover young of year cover for large mammals.

Grazing Interpretations.

This site suitable for summer grazing by domestic livestock.
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 site are in hydrologic group B. They have low to moderate runoff potential.

Recreational uses

This site has limited recreational values. It offers some hunting, hiking, horseback riding, and photographic opportunities. Off-road vehicle use can also occur.

Wood products

None

Other products

None

Other information

Field Offices

American Falls, ID
Blackfoot, ID
Burley, ID
Driggs, ID
Idaho Falls, ID
Malad, ID
Pocatello, ID
Rexburg, ID
Soda Springs, ID
St. Anthony, ID

Revision Notes: “Previously Approved” Provisional
This Provisional ecological site concept has passed Quality
Control (QC) and Quality Assurance (QA) to ensure that the site
meets the 2014 NESH standards for a Provisional ecological site
description. This is an updated “Previously Approved” ESD that
represents a first-generation tier of documentation that, prior to the
release of the 2014 National Ecological Site Handbook (NESH),
met all requirements as an “Approved” ESD as laid out in the 1997
(rev.1, 2003) National Range and Pasture Handbook (NRPH). The
document fully described the Reference State and Community
Phase in the State-and-Transition model. All other alternative
states are at least described in narrative form. The “Previously
Approved” ESD has been field-tested for a minimum of five years
and is a proven functional document for conservation planning.
The “Previously Approved” ESD does not contain all tabular and
narrative entries as required in the current “Approved” level of
documentation, but it is expected that the “Previously Approved”
ESD will continue refinement toward an “Approved” status.

Site Development and Testing Plan:
Future work, as described in a Project Plan, is necessary to
validate the information in this Provisional Ecological Site
Description. This will include field activities to collect low-,
medium-, and high-intensity sampling, soil correlations, and
analysis of that data. Annual field reviews should be done by soil
scientists and vegetation specialists. The final field review, peer
review, quality control, and quality assurance reviews of the ESD
will be required to produce the final document.

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
Lee Brooks, Range Management Specialist, IASCD
Kristen May, Resource Soil Scientist, NRCS, Idaho

Type locality

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”.
Petersen, S.L., 2004. A Landscape-Scale Assessment of Plant Communities, Hydrologic Processes, and State-and-Transition Theory in a Western Juniper Dominated Ecosystem. PhD Dissertation. Oregon State University, Corvallis, Oregon.

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/feis
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