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:

   No rills expected. A few minor rills may form on slopes greater that 5% due to moderate permeability and moderate runoff.

2. Presence of water flow patterns:

   Water flow patterns are infrequent, short (1 to 2 meters), and poorly developed with less than 10% coverage. They may become more common on steeper slopes due to slow to moderate permeability and medium runoff characteristics of the soils.

3. Number and height of erosional pedestals or terracettes:

   Pedestals less than 1” may be common and often associated with water flow patterns. Terracettes are infrequent, but they should be short. Both may be more developed and common during a drought, due to moderate wind erosion hazard of the soils. Moderate wind erosion hazard occurs on the soils with a coarse-loamy surface textures. Pedestals and terracettes may be more common, especially on steeper slopes, but they should be short.

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

   Bare ground ranges from 30-50%. Drought may cause an increase in bare ground.

5. Number of gullies and erosion associated with gullies:

   None

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

   No blowouts are present on this site. Some small mounding around long-lived perennial plant bases common, especially during droughts, due to low to moderate wind erosion hazard of the soil.

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

   Most herbaceous and fine woody litter will be transported by wind and in short water flow pathways, while a small percentage stays in place. Coarse woody litter and duff will accumulate under shrub and tree canopies.

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

   Soil aggregate stability ratings should average 4-5 (range 3 to 6) under plant canopies and 2-3 (range 1 to 3)in the interspaces. There is usually less than 5% cover of rock fragments on the surface. When well vegetated, soils have a moderate resistance to water erosion and moderate to high resistance to wind erosion

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

   Soil structure is mostly granular (weak to moderate, very fine and fine) with some platy (weak, thin and medium) and sub angular blocky (weak, fine to medium). Surface thickness typically ranges from 2-8 inches, but is mostly 2-4 inches. Color is typically reddish brown to brown, but can vary depending on parent material.

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

    This site is characterized by a relatively even distribution of mostly grasses with some shrubs and a few forbs. This type of plant community is moderately effective at capturing and storing precipitation thus reducing runoff. Cover averages 30-40% (25 to 30% grasses, 5-10% shrubs, 2-5% forbs). Basal plant cover averages 10-20% (15% grasses, 2% shrubs, 1% forbs). Both cover values decrease during a prolonged drought.

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

    The occurrence of compaction layers should be rare to none. Soils with sandy clay loam and clay loam textures, can be easily compacted when wet, if there are no rock fragments in surface horizons. Some surface horizons are naturally platy.

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:

    >40%: None

    Sub-dominant:

    11-40%: warm season bunchgrasses > warm season colonizing grasses > shrubs > cool season bunchgrasses >

    Other:

    Minor (3-10%): forbs = cacti = trees(trace)

    Additional:

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

    In a normal year up to 10% of grasses and shrubs die off. During and after drought years there can be from 10 to 15% die off of shrubs and grasses. Severe winter droughts affect shrubs, trees and cool season grasses the most. Severe summer droughts affect the warm season grasses the most.

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

    Average percent litter cover ranges from 20-40% and depth 1/8”inch. Within plant interspaces litter ranges from 5 to 20% cover ,while under shrub and tree canopies litter can range up to 50% cover with depths from 1/8 to 1/4 inch thick.

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

    Total production ranges from; 300-375 pounds per acre (dry weight) in drought years; 572-725 pounds per acre in average years; 725-800 pounds per acre in wet 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:

    Mormon tea (EPVI), Broom snakeweed (GUSA2), Greene''s rabbitbrush (CHGR6), Prickly pear (OPPO), Whipple cholla cactus (CYWH) and false buffalo grass (MUSQ) are all native to the site, but have the ability to increase and dominate the area after unmanaged grazing. Oneseed juniper (JUMO) is native to the site, but has the ability to increase and dominate the site after unmanaged grazing and/or fire exclusion. Russian thistle (SATR12) is an exotic forb that has the ability to increase and dominate the site after heavy grazing and/or ground disturbance.

17. Perennial plant reproductive capability:

    All plants native to this site are adapted to the climate and are producing seeds, stolons and rhizomes in all but the most severe droughts.

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