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.

Indicators

1. Number and extent of rills:

   None to Very Few. Some very minor rill development may be evident following significant thunderstorm or snow melt events, but they should mostly heal during the following growing season. The presence of rill development may also be more apparent on steeper slopes (> 15%) or where run-on from adjacent upland sites or exposed bedrock concentrate flow. Any rill development present should be less than 1 inch deep, moderately short (< 6’) and spaced a minimum of 10 to 12 feet apart.

2. Presence of water flow patterns:

   Very Few. A very few stable overland flow patterns may be present. They will typically wind around perennial plant bases. They should show no evidence of current erosion or deposition. Flow patterns present are normally 15 to 20 feet long, follow natural contours, and are typically spaced at least 10 to 15 feet apart. A slight increase in flow activity may be observed immediately following significant weather events such as thunderstorms or spring run-off events.

3. Number and height of erosional pedestals or terracettes:

   None. There should be no evidence of pedestals or terracettes caused by accelerated water erosion. One to 2 inches of elevational mounding under Mountain big sagebrush and other shrub canopies, and within biological soil crusts, is normal for this site and is not caused by water erosion. There are no exposed roots around perennial grasses and shrubs.

4. Bare ground from Ecological Site Description or other studies (rock, litter, lichen, moss, plant canopy are not bare ground):

   Bare ground ranges from 20% - 30%. Soil surface may be covered by 50 to 60% coarse fragments. Bare ground openings should not be greater than 2 to 3 feet in diameter and should normally not be connected.

5. Number of gullies and erosion associated with gullies:

   None at site level. Scattered landscape level gully channels, however, are a normal component of these environments. Where landscape gullies are present, they should be stable, partially vegetated on their sides and bottoms, with no evidence of head-cutting. Some slight increase in disturbance may be evident following significant weather events or when gullies convey considerable runoff from higher elevation rocky or naturally eroding areas.

6. Extent of wind scoured, blowouts and/or depositional areas:

   None. No evidence of wind generated soil movement is present. Slight depositional mounding within perennial grass crowns, under Mountain big sagebrush and other shrub canopies, and within biological soil crusts is normal for this site.

7. Amount of litter movement (describe size and distance expected to travel):

   The majority of litter accumulates in place at the base of plants canopies. Slight movement of the finest material (< 1/8 inch) may move 1 to 2 feet in the direction of prevailing winds or down slope if being transported by water. Little accumulation is observed behind obstructions.

8. Soil surface (top few mm) resistance to erosion (stability values are averages - most sites will show a range of values):

   This site should have a soil stability rating of 5 or 6 under plant canopies, and a 4 to 5 in the interspaces. Average should be a 5. Surface textures are typically gravelly loams, gravelly sandy loams, and sandy clay loams containing up to 50% coarse fragments.

9. Soil surface structure and SOM content (include type of structure and A-horizon color and thickness):

   (Bequinn) Soil surface is typically 0 to 5 inches deep. Surface texture is a very gravelly loam and structure is fine granular. The A-horizon color is dark brown (7.5YR 4/3). Soils have an Ochric epipedon that extends 12 inches into the soil profile. The A horizon is normally deeper and better developed under plant canopies.

10. Effect of community phase composition (relative proportion of different functional groups) and spatial distribution on infiltration and runoff:

    Spatial distribution of well developed biological soil crusts (where present) intercept raindrops, reducing splash erosion, and provide areas of surface detention to store water allowing additional time for infiltration. Crowns of trees and accumulating litter at base of trees appear to create a micro-topography that may enhance development of water flow patterns below the drip line of the canopy. On community phases within the reference state where juniper canopy increases, understory vegetation may be reduced causing an associated increase in runoff.

11. Presence and thickness of compaction layer (usually none; describe soil profile features which may be mistaken for compaction on this site):

    None, There may be dense layers of rock fragments or other naturally occurring hard layers found in the soil subsurface. These should not be considered to be compaction layers.

12. 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:

    Trees (Utah juniper)> Non-sprouting shrubs (Mountain big sagebrush, > Sprouting Shrubs (Mountain snowberry, bitterbrush) > Perennial bunchgrasses (bluebunch wheatgrass, Indian ricegrass) >> Perennial forbs (low beardstongue).

    Sub-dominant:

    Sprouting shrubs (green rabbitbrush, gray horsebrush) > = Warm season grasses (western wheatgrass).

    Other:

    A wide variety of other grasses and both perennial and annual forbs can be expected to occur in the plant community.

    Additional:

    Moss and lichen communities will normally be found under plant canopies while cyanobacteria can be found throughout the site. Functional/structural groups may appropriately contain non-native species if their ecological function is the same as the native species. Perennial and annual forbs can be expected to vary widely in their expression in the plant community based upon departures from average growing conditions.

13. Amount of plant mortality and decadence (include which functional groups are expected to show mortality or decadence):

    During years with average to above-average precipitation, there should be very little recent mortality or decadence apparent in trees, shrubs, or grasses. During severe (multi-year) drought up to 10% of the Utah junipers may die, either from drought, insect damage or pathogens such as mistletoe. There may be partial mortality on individual bunchgrasses and shrubs during drought periods, and complete mortality of individual plants during severe drought periods, particularly on the shallower and coarser soils associated with this site. Because woody stems may persist for many years, Utah junipers (especially older trees) will normally have dead stems within the plant canopy.

14. Average percent litter cover (%) and depth ( in):

    Litter cover averages fron 15 to 20% (including under plants) with the majority being fine litter. Depth should be 1 leaf thickness in the interspaces, up to 1/2” under shrub canopies, and up to 1” under tree canopies. Litter cover may increase to 30% on some years due to increased production of plants.

15. Expected annual annual-production (this is TOTAL above-ground annual-production, not just forage annual-production):

    Annual production in air-dry herbage should be approximately 550 to 650 pounds per acre on an average year. Production could vary from 400 to 850 pounds per acre during drought or above-average years.

16. 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, Russian thistle, alyssum, and mustard species are most likely to invade this site.

17. Perennial plant reproductive capability:

    All perennial plant species have the ability to reproduce in most years except drought years. There are no restrictions on either seed or vegetative reproduction. Some seedling recruitment of major species may be present during average or above average years.