Physiographic features

This site occurs on nearly level flats and benchlands to rolling hill slopes on all aspects. Slopes predominantly range from 0 to 20 percent, occasionally reaching 30 percent. Small lava rock outcrop areas may be scattered throughout the site. Elevations range from 3000 to 5600 feet (914 to 1707 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

Soils on this site are generally silt loams and loams. They may be gravelly or very gravelly but not in sufficient amounts to limit production. The soils are well to somewhat excessively drained and very deep to bedrock. Subsoils are medium textured and have a lime accumulation at depths from 8 to 18 inches. Substratum may be sand, gravel, basalt, or hardpan. The soils have low organic matter content and a moderate permeability moderate. The available water holding capacity (AWC) is low to moderate. Erosion hazard is generally moderate, but can be high when plant cover is scarce or lacking and slopes increase. These soils are characterized by a xeric soil moisture regime. The soils have either a mesic or frigid soil temperature regime.

Soil Series Correlated to this Ecological Site


Downey
Heglar
Pocatello
Sterling

Table 4. Representative soil features

Animal community

Animal Community:

Wildlife Interpretations.
Animal Community – Wildlife Interpretations

This rangeland ecological site provides diverse habitat for many native wildlife species. Large herbivore use of this ecological site is dominated by mule deer and pronghorn antelope. The height of sagebrush will influence the use of the site by pronghorn. Important seasonal habitat is provided for resident and migratory animals including western toad, sagebrush lizard, western rattlesnake, shrews, bats, jackrabbits, ground squirrels, mice, coyote, red fox, badger, sage-grouse, Ferruginous hawk, prairie falcon, horned lark, and western meadowlark. Encroachment of noxious and invasive plant species (cheatgrass, bulbous bluegrass, and knapweed) can replace native plant species which provide critical feed, brood-rearing, and nesting cover for a variety of native wildlife. Area sensitive species include pygmy rabbit, burrowing owl, 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 - Wyoming Big Sagebrush/ Bluebunch Wheatgrass/ Sandberg Bluegrass/ Thurber’s Needlegrass Reference Plant Community (RPC): This plant community provides a diversity of grasses, forbs, and shrubs used by native insect communities that assist in pollination. 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. Spring developments that capture all available water would preclude the use of these sites by amphibians. Native shrub-steppe obligate avian species include the Brewer’s sparrow, sage sparrow, sage thrasher, burrowing owl, and sage-grouse. Critical habitat (nesting, brood-rearing, and winter cover) for sage-grouse is provided by this diverse plant community. The plant community supports seasonal needs of mule deer and antelope, providing food and cover. Wyoming big sagebrush is a preferred browse species for wild ungulates. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, pygmy rabbits, and Great Basin pocket mice would utilize this plant community.

State 1 Phase 1.2 - Wyoming Big Sagebrush/ Sandberg Bluegrass Plant Community: This plant community is the result of improper grazing management and a lack of fire. An increase in canopy cover of sagebrush contributes to a sparse herbaceous understory. The reduced herbaceous understory results in lower diversity and numbers of insects. The reptile community will be similar to the State 1 Phase 1.1 reptile community. Reduced herbaceous understory is a key factor in reducing quality of the habitat for bird species. Shrub-steppe obligate bird species using site include Brewer’s sparrow, sage sparrow, sage thrasher, and sage-grouse. Quality of habitat (nesting and brood-rearing) for sage grouse is reduced due to a less diverse herbaceous plant community. Sage-grouse may use this area for winter cover and winter food. The plant community supports the seasonal needs of large mammals (mule deer and antelope) providing food and cover. Wyoming big sagebrush is desirable browse for ungulates. A diverse small mammal population including golden-mantled ground squirrels, jackrabbits, deer mice, pygmy rabbits, and Great Basin pocket mice may utilize this plant community.

State 1 Phase 1.3 - Bluebunch Wheatgrass/ Sandberg Bluegrass/ Bottlebrush Squirreltail Plant Community: This plant community is the result of wildfire. The plant community, dominated by herbaceous vegetation with little or no Wyoming sagebrush provides less vertical structure and limits use by shrub obligate animals. Patches of root sprouting shrubs (three-tip sagebrush and rabbitbrushes) may be present to provide limited vertical structure for wildlife. Insect diversity may be reduced, but a native forb plant community similar to that in State 1 Phase 1.1 would be present supporting select pollinators. Quality of reptile habitat would be poor until remaining root sprouting shrubs begin to provide similar habitat structure as in the State 1 phase 1.1 plant community. The dominance of herbaceous vegetation with little sagebrush canopy cover would reduce or eliminate use of this area for nesting by Brewer’s sparrow, sage sparrow, sage thrasher, and sage- grouse. This plant community provides limited brood-rearing habitat for sage-grouse if sagebrush cover is nearby. The site is not suitable as winter or nesting habitat for sage grouse. The herbaceous vegetation improves habitat for grassland avian species (horned lark and western meadowlark). Mule deer and pronghorn forage use would be seasonal (spring through fall) but the site would offer little thermal or young of year cover. Pronghorn may prefer this site over sites with dense tall sagebrush. Small mammal diversity and populations maybe reduced with a decrease in cover and increase in hunting success by predators.

State 2 - Sandberg Bluegrass/ Cheatgrass/ Bulbous Bluegrass/ Annual Plant Community: This plant community is the result of frequent fire. The loss of the native shrub and herbaceous plant community components would not support a diverse insect community. The reduced forb component in the plant community would support a very limited population of pollinators. Most native reptilian species are not supported with food, water, or cover. This plant community does not support the habitat requirements for sage-grouse, sage thrasher, Brewer’s sparrow, or sage sparrow. Diversity of grassland avian species is reduced due to poor cover and food. Birds of prey including hawks and falcons may range throughout these areas looking for prey species. Large herbivores may utilize the herbaceous vegetation in the early part of the year when the invasive annuals (cheatgrass) are more palatable. At other times of the year these large mammals would not regularly utilize these areas due to poor food and cover conditions. The populations of small mammals would be dominated by open grassland species.

State 3 - Range 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 species. Grassland animal species including western meadowlark, horned lark, savannah sparrow, deer mouse, pronghorn, mule deer, and kangaroo rat would utilize this site for forage or nesting. Birds of prey including hawks and falcons may range throughout this community looking for prey species.

Grazing Interpretations.

This site is best suited for livestock grazing in the spring, early summer and fall. Natural water supplies may be insufficient or absent and livestock water may have to be piped, hauled, or otherwise made available for livestock using this site.

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 A. When the hydrologic conditions of the vegetative cover are good, the natural erosion hazard is slight.

Recreational uses

This site has very little recreational value. It has some spring blooming flowers which offer slight aesthetic values. It has limited value for hunting pronghorn antelope, coyotes, rabbits, and mule deer. The site has little value for picnicking or camping. It has very little aesthetic appeal or natural beauty except where it is adjacent to lava flows.

Wood products

none.

Other products

none.

Other information

Field Offices

American Falls
Blackfoot
Burley
Driggs
Ft. Hall
Idaho Falls
Malad
Pocatello
Rexburg
Soda Springs
St. Anthony

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”.
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