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:

   Rills are none to rare. A few rills can be expected on steeper slopes in areas recently subjected to summer convection storms.

2. Presence of water flow patterns:

   Water flow patterns are none to rare but can be expected in areas recently subjected to summer convection storms, usually on steeper slopes. These are short (<1m) and not connected.

3. Number and height of erosional pedestals or terracettes:

   Pedestals are none to rare. Occurrence is usually limited to areas of water flow patterns.

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

   Bare Ground 10-15%; surface cover of rock fragments up to 75%; shrub canopy to 15%; foliar cover of perennial herbaceous plants ± 10%.

5. Number of gullies and erosion associated with gullies:

   None

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

   None

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

   Fine litter (foliage from grasses and annual & perennial forbs) expected to move distance of slope length (< 10 ft) during intense summer convection storms or rapid snowmelt events. Persistent litter (large woody material) will remain in place except during large rainfall events.

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

   Soil stability values should be 3 to 6 on most soil textures found on this site. (To be field tested.)

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

   Surface structure is typically moderately thick to weak thin platy. Soil surface colors are pale brown to very dark brown when moist. Organic matter of the surface 2 to 4 inches is typically less than 1 percent dropping off quickly below. Organic matter content can be more or less depending on micro-topography.

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

    Shrub canopy and associated litter provide some protection from raindrop impact.

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

    Compacted layers are none. Subsoil paralithic horizons or duripans are not to be interpreted as compacted.

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:

    Mojave Desert shrubs

    Sub-dominant:

    Warm-season, perennial bunchgrasses > cool-season, perennial bunchgrasses > perennial forbs > annual grasses = annual forbs.

    Other:

    Additional:

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

    Dead branches within individual shrubs common and standing dead shrub canopy material may be as much as 25% of total woody canopy; some of the mature bunchgrasses (<10%) have dead centers.

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

    25 to 30 percent, under canopy and interspaces <1/4 inch in depth

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

    For normal or average growing season ± 250 lbs/ac. Favorable years ±400 lbs/ac and unfavorable years ±150 lbs/ac.

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:

    Potential invaders on this site include red brome, redstem filaree, annual mustards and Mediterranean grass.

17. Perennial plant reproductive capability:

    All functional groups should reproduce in average (or normal) and above average growing season year. Little growth or reproduction occurs during extreme or extended drought periods.

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