Principles of Vegetation Measurement & Assessment
and Ecological Monitoring & Analysis


Veg Sampling
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Assessing Rangeland Health

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Monitoring Vegetation Community Health

The "Rangeland Health" Concept

Land managers and advisors who work on rangelands need an idea of how healthy the land is to guide management and restoration efforts to sustain ecosystems. Is the range healthy? A simple question, but a difficult one to answer.  Rangeland health is “the degree to which the integrity of the soil, vegetation, water and air as well as the ecological processes of the rangeland ecosystem are balanced and sustained." Integrity is defined as the "maintenance of the functional attributes characteristic of a locale, including normal variability." (National Research Council. 1994. As cited in Pyke et al. 2002 in the Journal of Range Management.)

Overview of Rangeland Health Assessment

The following information was taken from USGS Fact Sheet 125-02 published in 2002.

Ecological processes functioning within a normal range of variation support a diverse mixture of plant and animal communities. These ecological processes include:

  • water cycle—the capture, storage, and redistribution of precipitation;
  • energy flow—conversion of sunlight to plant and animal matter; and
  • nutrient cycles—the cycle of nutrients such as nitrogen and phosphorus through the physical and biotic components of the environment.

Due to the complexity of ecological processes and their interrelationships, it is usually difficult or expensive to directly measure site integrity and the status of ecological processes. Therefore, biological and physical attributes are often used to indicate the functional status of ecological processes and site integrity.

The U.S. Geological Survey (USGS), Agricultural Research Service (ARS), Bureau of Land Management (BLM), and Natural Resources Conservation Service (NRCS) developed a technique to assess rangeland health. Because rangelands are complex ecosystems, it is difficult to attain a single rating of rangeland health. This technique assesses separately three attributes of land health.

Rangeland Health Attributes:
  • Soil/site stability—the capacity of the site to limit redistribution and loss of soil resources (including nutrients and organic matter) by wind and water.
  • Hydrologic function—the capacity of the site to capture, store, and safely release water from rainfall, run-on, and snowmelt (where relevant), to resist a reduction in this capacity, and to recover this capacity following degradation.
  • Integrity of the biotic community—the capacity of the site to support characteristic functional and structural communities in the context of normal variability, to resist loss of this function and structure due to disturbance, and to recover following disturbance.

Indicators are components of a system whose characteristics (e.g., presence or absence, quantity, of distribution) are used as an index of an attribute that is too difficult, inconvenient, or expensive to measure. Several indicators must be used to gain an understanding about each attribute of land health. By using a qualitative, observational procedure, the functional status of such indicators can be assessed.

This fast assessment technique includes both plant and soil indicators that can help educate the interested publics, private landowners, and agency land managers about interpreting and assessing rangeland health. In the past, indicators used in rangeland monitoring and resource inventories by land managers and technical assistance agencies have focused on vegetation (e.g., production, composition, density) or soil stability and were used to indicate rangeland condition or livestock carrying capacity. Such single indicator assessments are inadequate to determine rangeland health because they do not reflect nor assess the complexity of ecological processes. Rather than a single indicator, a suite of key indicators should be used for an assessment.

In the "Rangeland Health" system, 17 indicators are used to gauge the three rangeland health attributes: soil/site stability, hydrologic function, and the integrity of the biotic community of selected rangeland ecological sites.

Examples of Indicators:

Details of Rangeland Health Assessment

A full manual of assessing rangeland health -- "Interpreting Indicators of Rangeland Health" (Version 4) -- was published in 2005 as Technical Reference 1734-6. Download as a Acrobat PDF file (5.7 Mb) for full details.

View this PowerPoint Presentation for a more detailed over view of how Rangeland Health indicators are determined and assessed. 

Summary Questions

  1. What is the importance of a referent in rangeland health assessment?

  2. What are two indicators used in the assessment of hydrologic function?

  3. Is this rangeland health assessment based on qualitative or quantitative measurements?

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