Physiographic features

This site generally occurs on nearly level to moderately sloping mountain slopes, uplands, lava plains and fan remnants. Slopes range from 0 to 15 percent on all aspects. Elevations range from 6300 to 7400 feet (1925 to 2250 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 generally moderately deep to very deep loams and gravelly loams. A few stones may be present in the profile. The soils are well drained and have slow to moderate permeability. Runoff is low to medium. Available water capacity is very low to moderate. These soils are characterized by a xeric soil moisture regime and a cryic soil temperature regime.

Soil Series Correlated to this Ecological Site


Raynoldson
Shotgun
Stringam

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 – Mountain Big Sagebrush/ Idaho Fescue/ 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 rattlesnake, Great Basin spadefoot toad, 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 bird species utilizing the habitat include the Brewer’s sparrow, sage sparrow, sage grouse, and sage thrasher. Sage-grouse habitat (leks, nesting, 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. Antelope bitterbrush may be present in this plant community, and along with bluebunch wheatgrass and Idaho fescue is an important forage species for these animals. Some areas (south and west facing slopes) may provide winter food for mule deer and elk. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, and Great Basin pocket mice may utilize this plant community. The deer mouse is beneficial to this site as it is the principal vector for planting bitterbrush seed.

State 1 Phase 1.2- Mountain Big Sagebrush/ Utah Juniper/ Idaho Fescue/ Mountain Brome Plant Community: This phase has developed due to fire return intervals being much longer than normal and/or improper grazing management. An increase in canopy cover of sagebrush and juniper contributes to a reduced herbaceous understory. The reptile community will be similar to the State 1 Phase 1.1 community represented by common sagebrush lizard and western rattlesnake. Sagebrush provides brood-rearing, nesting, winter cover, and winter food habitat for sage-grouse but as understory vegetation declines and juniper increases the quality of this habitat is reduced. The plant community provides spring through fall forage for mule deer, elk, and moose. Quality of winter food habitat for mule deer and elk is similar to that in State 1 Phase 1.1. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, and Great Basin pocket mice may utilize this plant community.

State 1 Phase 1.3 – Mountain Brome/ Slender Wheatgrass/ Idaho Fescue Plant Community: This plant community is a result of recent wildfire, prescribed burning, or brush management. The plant community, dominated by herbaceous vegetation with little to no sagebrush or antelope bitterbrush would provide less vertical structure for animals. Patches of root sprouting shrubs (snowberry and rabbitbrush) may be present to provide limited vertical structure for wildlife. Insect diversity would be reduced but a native forb plant community similar to that of State 1 Phase 1.1 would still support select pollinators. Habitat for reptiles identified in State 1 Phase 1.1 would be reduced due to the loss of sagebrush. Amphibian habitat would be tied to permanent spring sites in the area. Development of spring sites that collected all available water would exclude the use of amphibians on these sites. The dominance of herbaceous vegetation with little sagebrush or antelope bitterbrush canopy cover would limit use of these areas as nesting habitat by Brewer’s sparrow, sage sparrow, sage grouse, and sage thrasher. The dominant herbaceous vegetation improves habitat for grassland avian species (horned lark, savannah sparrow, vesper sparrow, and western meadowlark). Sharp-tailed grouse would prefer this plant community over sites with dense sagebrush. Mule deer and elk use would be seasonal (spring, summer, and fall) but the site would offer little thermal or young of year cover due to the loss of shrub cover. Pronghorn antelope may utilize this open grassy site. 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 1 Phase 1.4 – Mountain Big Sagebrush 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. 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 community. The reduced diversity of insects and understory cover may reduce the quality of food and cover for reptile populations. Native shrub-steppe obligate bird species utilizing the habitat include the Brewer’s sparrow, sage sparrow, sage grouse, and sage thrasher. Sagebrush provides brood-rearing, nesting, winter cover, and winter food habitat for sage-grouse but as understory vegetation declines the quality of this habitat is reduced. The plant community supports limited spring and fall forage for mule deer, elk, and moose due to the loss of understory vegetation. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, and Great Basin pocket mice may utilize this plant community.

State 2 – Annuals/ Forbs/ Cheatgrass/ Bulbous Bluegrass Plant Community: This state has developed due to improper grazing management and frequent fire. The reduced forb and shrub components in the plant community would support a very limited population of pollinators. Habitat for common sagebrush lizard, Great Basin spadefoot toad, and western toad would be reduced or eliminated due to the loss of sagebrush. The loss of sagebrush and antelope bitterbrush would eliminate habitat for sage thrasher, Brewer’s sparrow, sage-grouse, and sage sparrow. 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 vegetation is more palatable. The populations of small mammals would be dominated by open grassland species. Predator hunting success would increase due to the reduced amount of cover for small mammals. Large blocks of this plant community would fragment the reference plant community and reduce the quality of habitat for shrub-steppe obligate animal species.

State 3 – Rocky Mountain Juniper/ Annuals/ Cheatgrass/ Bulbous Bluegrass Plant Community: This state has developed due to improper grazing management and lack of fire. The loss of native understory vegetation will reduce insect diversity on the site. The lack of flowering plants reduces use by pollinators like butterflies and moths. Habitat for common sagebrush lizard, Great Basin spadefoot toad, and western toad would be reduced due to the loss of sagebrush and native understory vegetation. 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. As juniper encroaches the site will provide additional thermal cover for large mammals. The plant community provides food and cover for mule deer.

State 4 – Rangeland Seeding Plant Community: The seeding mixture (native or non-native) determines the animal species that utilize this site. A diverse seed mixture of grasses and forbs would provide similar habitat conditions as in the herbaceous plant community described in State 1 phase 1.3. A diverse seed mixture of grasses, forbs and shrubs would provide similar habitat conditions as described in State 1 phase 1.1 or 1.2. A monoculture of non-native grass species would not support diverse populations of insects, reptiles, avians, mammals, or shrub-steppe obligate animal species. Grassland animal species including western meadowlark, horned lark, savannah sparrow, deer mouse, kangaroo rat, mule deer, and elk would utilize this site for nesting and/or foraging. Birds of prey including hawks and falcons may range throughout this community looking for prey species. Large areas of State 4 with no shrubs in the plant community would fragment the reference plant community and would severely reduce the quality of the habitat for shrub-steppe obligate animal species.


Grazing Interpretations.

This site is best suited for grazing by livestock in the summer.
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. When the hydrologic condition of the vegetation is good, natural erosion hazard is slight.

Recreational uses

This site is used for hunting, hiking, horseback riding, and viewing and photography of blooming forbs. The site is also used by ATV’s and snowmobiles.

Wood products

Mature juniper that has invaded and increased on the site can be cut for posts, poles, firewood, and lumber.

Other products

none.

Other information

Field Offices

American Falls, ID
Blackfoot, ID
Burley, ID
Driggs, ID
Ft. Hall, 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

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.
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/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