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:

   Some rills may be present, and their appearance may intensify where slopes approach 80% . Their expression may be less defined where coarse fragments (i.e., cobbles or gravels) dominate the soil surface. Rill occurrence may increase slightly on areas located below exposed bedrock or other water shedding areas where increased runoff may occur. Rills should be <1 inches deep, somewhat long (10 to 15 feet) and somewhat widely spaced (8-12 feet). An increase in rill development may be observed immediately following major thunderstorm or spring runoff events.

2. Presence of water flow patterns:

   Sinuous flow patterns are common and wind around perennial plants and surface rock. Evidence of flow patterns is expected to increase somewhat as slopes approach 80%. Water flow patterns are long (20 to 30 feet), somewhat narrow (1 to 2 feet wide), and spaced widely (5 to 10 yards) and more closely spaced(3 to 6 yards) on slopes nearing 70 to 80%.

3. Number and height of erosional pedestals or terracettes:

   Small pedestals will form at the base of plants that occur on the edge of water flow patterns, 2 to 4% of plants show minor exposed roots. Terracettes are fairly common, forming behind debris dams of small to medium sized litter (up to 2 inches in diameter) in water flow patterns. These debris dams may accumulate smaller litter (leaves, grass and forb stems) and sediment.

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

   20–25%. (Soil surface is typically covered by 40-60% surface fragments). Most bare ground is associated with water flow patterns, rills, and gullies. Bare ground spaces not associated with flow patterns should not be greater than 1 to 2 feet in diameter.

5. Number of gullies and erosion associated with gullies:

   A few gullies may occur. Any gullies present may extend down the length of the site until they reach a stream or other area where water and sediment is diverted or accumulates. Gullies show slightly more indication of erosion as slopes approach 80%, or where the site occurs adjacent to watershed areas with concentrated flow patterns.

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

   None. Perennial shrubs along with surface coarse fragments on this site help break the wind and reduce the potential for wind erosion.

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

   Because of the sites very steep slopes, some litter redistribution downslope caused by water movement is normal. Some litter removal may occur in flow channels with deposition occurring within 3 to 5 feet at points of obstruction. The majority of litter still accumulates at the base of plants. Some grass leaves, stems and small woody twigs may accumulate in soil depressions adjacent to plants. Woody stems are likely to move 1 to 2 feet. A slight increase in litter movement is expected following runoff resulting from heavy spring runoff or thunderstorms.

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 an erosion rating of 5 or 6. Vegetation cover, litter, biological soil crusts and surface rock reduce erosion.

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

   (Gappmayer) Soil surface A horizon is typically 0 to 6 inches deep. Surface texture is a cobbly light loam which may have an organic mat of partially decomposed leaves and twigs 2 inches deep on the surface. Structure is weak very fine granular. Color is very dark grayish brown (10YR 3/2). A Mollic epipedon extends 19 inches into the soil profile. Use the specific information for the soil you are assessing found in the published soil survey to supplement this description.

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

    Good spatial distribution of plants and well developed biological soil crusts (where present) intercept raindrops, reducing splash erosion and providing areas of increased surface detention to store water, allowing additional time for infiltration.

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

    None. Some soils may have natural textural variability within their profiles, including changes in clay and coarse fragment content, these should not be mistaken for a compaction pans.

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:

    Sprouting shrub (Gambel Oak) >> Non-sprouting shrubs (Mountain big sagebrush) > cool season perennial grasses (bluebunch wheatgrass, muttongrass) >> rhizomatous grasses (slender wheatgrass).

    Sub-dominant:

    forbs (thickleaf peavine, shortstem wild buckwheat)

    Other:

    Functional/structural groups may appropriately contain non-native species if their ecological function is the same as the native species in the reference state. Biological soil crust is variable in its expression where present on this site and is measured as a component of ground cover. Forbs can be expected to vary widely in their expression in the plant community based upon departures from average growing conditions.

    Additional:

    Factors contributing to temporal variability include insects and other pathogens (mistletoe), drought, extreme precipitation events, etc. Factors contributing to spatial variability include slope, amount of rock fragments, aspect, etc. Following a recent disturbance such as fire, drought or insects, that may remove the woody vegetation, forbs and perennial grasses (herbaceous species) may become more dominate in the community. These conditions may reflect different functional community phases within the reference state.

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

    There may be partial mortality on individual bunchgrasses and shrubs during drought periods, and complete mortality of individual plants during severe drought periods. Following fire, mature oak will die but vigorous re-sprouting of young oak seedlings is common. Hard spring frosts can kill gambel oak.

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

    Cover should be composed mostly of fine litter. Depth should vary from a 1 thickness in the interspaces, to up to 1 1/2 under herbaceous canopies, and up to 2” under shrub canopies. Litter cover may increase to 35% 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 1800 - 1900#/acre on an average year, but could range from 1400 to 2300#/acre during periods of prolonged drought or above average precipitation.
    
    

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:

    Few invasive species are capable of dominating this site. When invasion does occur, cheatgrass, alyssum, and mustard species are the most likely species to invade.

17. Perennial plant reproductive capability:

    All perennial plants should have the ability to reproduce in all years, except in extreme drought years. There are no restrictions on either seed or vegetative reproduction. Some seedling recruitment of major species is present during average and above average growing years.

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