Interpreting Indicators of Rangeland Health is a qualitative assessment protocol for determining the condition of rangeland ecosystems against a reference condition that is determined ahead of time for each ecological site. Interpreting Indicators of Rangeland Health is based on 17 quickly-assessed qualitative indicators that provides a preliminary evaluation of soil/site stability, hydrologic function, and biotic integrity (at the ecological site level). The product of this assessment is not a single rating of rangeland health, rather a qualitative assessment of these three components which are referred to as attributes.
A key principle of this protocol is first determining the ecological site for the area being assessed and then the development of a “reference sheet” that describes the condition of the ecological site in the absence of degradation. Ecological processes are described relative to referece states for the ecological sites being evaluated, requiring a reference sheet describing the range of spatial and temporal variability expected for soils and plant communities in the reference state within each ecological site. The ecological site determines what is possible on a site. For each ecological site, a state-and-transition model depicts what types of vegetation are likely to occur given the natural and management regimes and history of the site. Both the ecological site description and state-and-transition models are used as the basis for developing the reference sheet for Interpreting Indicators of Rangeland Health.
This protocol was developed to be used by experienced, knowledgeable land managers and technical specialists, requiring a strong understanding of the ecological sites that are being evaluated and the associated ecological processes, vegetation, and soils for each site. It is intended to be used by a team of at least two or more individuals (e.g., an ecologist and soil scientist) working together. Because assessment protocol requires reference information for the ecological sites being evaluated, reference sheets are required. Reference sheets are currently being developed and incorporated into the ecological site descriptions, however if they do not exist for a particular site, additional expertise is required to develop a reference sheet.
This protocol provides users with a qualitative assessment of rangeland health that provides land managers and resource specialists with an effective tool to communicate fundamental ecological concepts to a wide variety of audiences. It is also a useful tool to help select monitoring sites when developing monitoring programs. Finally, this protocol is used to provide early warning signs of potential problems and opportunities by helping land managers identify areas that are potentially at risk of degradation or where resource problems currently exist. It is important to note that this protocol is NOT to be used to identify the cause(s) of resource problems, independently make grazing and other management decisions, monitor land to determine trend, or independently generate national or regional assessments of rangeland health.
Interpreting Indicators of Rangeland Health is based on qualitative indicators that provides a preliminary evaluation of soil/site stability, hydrologic function, and biotic integrity (at the ecological site level). Indicators are defined as elements of an ecosystem used to assess process that are too difficult or time consuming to measure directly.
The product of this assessment is not a single rating of rangeland health, rather a qualitative assessment of these three components which are referred to as attributes. A suite of 17 key indicators are used to describe the three attributes mentioned above. Ecological processes are described relative to referece states for the ecological sites being evaluated, requiring a reference sheet describing the range of spatial and temporal variability expected for soils and plant communities in the reference state within each ecological site. Optional indicators can be included as necessary or appropriate for specific objectives (e.g., for biological crusts in areas where it's meaningful), but in general, none of the 17 indicators should be dropped from the protocol. This is to maintain consistency between assessments and because indicators that have not shown change in the past may begin to show change in the future due to changing or new processes.
|1. Rills||Small erosion rivulets that are generally linear and do not necessarily follow the micro-topography (unlike water flow patterns)||S,H|
|2. Water Flow Patters||The path that water takes (i.e., accumulates) as it moves across the soil surface during overland flow||S,H|
|3. Pedestals and/or Terracettes||Pedestals are rocks or plants that appear elevated as a result of soil loss by wind or water erosion. Pedestals can occur for reasons other than erosion, so it is important to determine that observed pedestals are indeed the product of erosional processes. A terracette is a bench of soil deposition behind an obstacle caused by water (not wind) movement.||S,H|
|4. Bare Ground||Amount of land surface not covered by vegetation, rock, litter, visible biological crusts, and stand dead vegetation||S,H|
|5. Gullies||A channel cut into the soil by the action of running water. Natural flow patterns that have never eroded are not gullies||S,H|
|6. Wind Scour or Deposition||Evidence of wind erosion. Erosion from interspaces and/or deposition under plants||S|
|7. Litter Movement||Degree and amount of litter (i.e., dead plant material in contact with the soil surface) movement (e.g., redistribution) and size of litter moved||S|
|8. Soil Surface Resistance to Erosion||This indicator reflects resistance of soil particles to detachment and loss by raindrop impact and overland flow||S,B|
|9. Soil Surface Loss & Degradation||The loss or degradation of the surface horizon of the soil. The two primary soil properties used to make this evaluation are the organic matter content and the structure of the surface layer or horizon.||S,B|
|10. Plant Community Composition and Distribution Relative to Infiltration and Runoff||The ability of a plant community - plant composition and distribution - to safely capture, store, and release precipitation.||H|
|11. Compaction||A near surface layer of dense soil caused by repeated impacts on or disturbances of the soil surface. Does not include textural or structural changes to soil.||S, H, B|
|12. Functional/Structural Groups||Suite of species that are grouped together based on similar photosynthetic pathways, plant size and structure, rooting depth and structure, nitrogen fixing ability, life cycle, etc. Where relevant, includes biological crusts.||B|
|13. Plant Mortality and Decadence||The proportion of dead or decadent to young or mature plants in the community, relative to that expected for the site under normal disturbance regimes.||B|
|14. Litter Amount||Departure from reference includes both too much or too little litter.||H,B|
|15. Annual Production||Net quantity of all above ground vascular plant material produced in a year||B|
|16. Invasive Plants||Plants (native or non-native) that will continue to increase on a site and become dominant or co-dominant (in terms of ecological processes) if not actively controlled by management intervention.||B|
|17. Reproductive Capability of Perennial Plants||The ability of native or seeded plants to produce seed, seedling, or vegetative reproductions in weather conditions allow. Presence/absence of young plants and seedlings is not used for this indicator.||B|
S = Soil and site stability, H = Hydrologic function, B = Biotic integrity
The following flow diagram from the Interpreting Indicators Manual (version 4) illustrates the process for applying the indicators. Interpretation of the indicators is tied directly to ecological sites, so it it critical that the ecological site be determined first before doing any other assessments.
Image source: Pellant et al. 2005. Interpreting Indicators of Rangeland Health, v4
Each of the 17 indicators is assessed on a sliding scale of five categories based on evaluation of the field condition against the site's reference sheet key using the following categories:
Once all of the indicators are assessed, those indicators related to soil and site stability are combined to get an overall rating for that attribute. This process is repeated for hydrologic function and biotic integrity to get three overall ratings for the site. Collapsing the three indicators into a single overall indicator is discouraged because it combines different attributes that may not be equivalent or equally weighted.
This protocol is a qualitative assessment that provides a preliminary evaluation of soil/site stability, hydrologic function, and biotic integrity and is NOT intended to be used to identify the cause(s) of resource problems, independently make management decisions, or determine trend. It can be useful when combined with other quantitative methods, and can help identify processes responsible for decreases in rangeland health. A limitation to using this protocol, however is that it requires a high level of expertise and should be used by experienced, knowledgeable land managers and technical specialists with a strong understanding of the ecological sites being evaluated and the associated ecological processes, vegetation, and soils for each site. In addition, if reference sheets are not available for the area being evaluated, additional expertise is required to develop a reference sheet.
While there are other qualitative site ranking methods like Pasture Condition Scoring and Site Condition Assessment, Interpreting Indicators of Rangeland Health is the only one that is designed around a broad suite of indicators to assess soil and site stability, hydrologic function, and biotic integrity. A number of other methods (e.g., Step Point for estimating cover or estimating plant production) are often used when implementing the Rangeland Health Indicators.
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