An Overview of Interpreting Indicators of Rangeland Health:Moving From Version 3.0 to 4.0SRM Annual MeetingCasper, Wyoming Feb. 6, 2003

Overview: History & TraditionEarly SurveysVegetation SuccessionRoots of Rangeland Status Traditional ApproachesRangeland ConditionCurrent NeedsEcosystem Processes

Early SurveysUSDA 1869 1905Division of Botany (1869)Botanical Surveys of the nationDivision of Ornithology & Mammalogy (1885-6)Bird and Mammal Surveys Division of Agrostology (1895)Investigate grass, forage and range management

Carrying Capacity SurveysUS Forest Service early 1900sGrazing on Forest ReservesAllowed if it did not impact water conservationCarrying Capacity Appraisals 1905 Indicated that carrying capacity was being reduced by overgrazing

Mixed Grass PrairieOvergrazed Shortgrass sod

Succession & Rangeland ConditionArthur Sampson 1919Grazing shifts plant cover and species compositionE. J. Dyksterhuis (1949)Range Condition ClassificationClassified plants into Increasers, Decreasers and Invaders relative to grazingExcellent, Good, Fair & Poor

Range Cond. & Linear Succession

Other TechniquesParker Three-step (BLM & USFS 1950s)Cover for Range ConditionSoil Surface Factors Soil-based ConditionNested FrequencyUtilization measurements

Focused on Livestock Use Key Area A relatively small portion of rangeland selected because of its location, use or grazing value as a monitoring point for grazing use.

Key Species Forage species whose use serves as an indicator to the degree of use of associated species.

1994Smith et al. 1995 JRMFocused on Biological & Physical Processes

Rangeland Health & Community States

The National Research Councils book on Rangeland Health incorporated concepts of these state and transition models when they suggested that thresholds may be crossed when a community becomes, in their words, unhealthy.

They advocated looking for assessment and monitoring techniques that might provide warnings of problems before thresholds are crossed; represented by there at risk section in this diagram.

As we continue to present this procedure to you, we will attempt to interweave these recent concepts on succession and community dynamics.

You will need to be able to recognize that each ecological site might support a series of potential communities and evaluate indicators that may provide us an assessment of the sites soil stability, hydrologic functioning and biotic integrity of the site.

Interagency/Academia Meeting Rangeland Health AssessmentOgden, UT- April, 1994

Interpreting Indicators of Rangeland HealthRangelandHealthProtocol

Rangeland HealthThe degree to which the integrity* of the soil, vegetation, water, & air as well as the ecological processes of the rangeland ecosystem are balanced and sustained.

* Integrity is the maintenance of the functional attributes characteristic of a locale, including normal variability

Ecological ProcessesEnergy flow the conversion of sunlight to plant and then animal matter.Nutrient cycle the movement of nutrients, such as carbon and nitrogen, through the physical and biotic components of the environment.Water cycle the capture, storage, & safe release of precipitation.

Westoby and others provided an excellent diagram that showed the vegetational composition shifting along a condition scale with grazing disturbance or with moisture.

Based on the linear concept of succession, removal of grazing pressure should allow the successional tendency of the community to express itself.

Drought will slow recovery or speed retrogression, while above-normal precipitation should speed progressive succession toward a climax or potential natural community.

However, people began to realize that removal of the grazing disturbance often was not enough to allow the community to return to its pre-disturbance composition.