Understanding Grazing Impacts is a reference guide that uses the indicator concept to predict direct and indirect grazing impacts based on grazing strategies selected.
Photo courtesy of USDA NRCS
The condition of rangeland has traditionally been evaluated with indicators such as bare soil and forage plant occurrence. Now rangeland managers can expand this process to assess ecosystem health based on different grazing management strategies. Evaluating rangeland health with environmental indicators is similar to evaluating people's health by measuring factors from blood pressure to white cell count to cholesterol.
The criteria and indicators concept is widely recommended and used for evaluating ecosystem health. In a 1994 report called Rangeland Health, the National Research Council recommended that federal agencies coordinate developing a process to evaluate rangeland health using the criteria and indicators concept.
In February 1995 the U.S. government agreed in principle to the "Santiago Declaration", a UN-sponsored conference on the environment that adopted using the criteria and indicators concept to measure sustainable forest management practices.
In October 1995 the USDA Forest Service produced a draft publication called A Report to Facilitate Discussion of Indicators of Sustainable Forest Management, which included many indicators that would also be appropriate for sustainable rangeland management.
In 2000 the U.S. Departments of Interior and Agriculture issued an interagency publication called Interpreting Indicators of Rangeland Health (TR 1734-6), which uses 17 indicators to evaluate how the ecological processes on a site are functioning. This publication was updated in 2005. http://www.glti.nrcs.usda.gov
In 2001 the Sustainable Rangelands Roundtable was established as a consortium of organizations, agencies and universities to identify criteria and indicators for describing and evaluating sustainable rangelands. In February 2003 the consortium proposed 5 criteria with 67 environmental, economic and social indicators. http://sustainablerangelands.warnercnr.colostate.edu/
Understanding Grazing Impacts is a web site that uses the indicator concept to predict direct and indirect grazing impacts based on grazing strategies selected. To help ranch and land managers predict the positive and negative effects of livestock grazing on rangeland ecosystems, this guide focuses on environmental indicators that can be measured and that are relatively well understood.
The use of indicators allows managers to effectively evaluate the impact of different livestock grazing strategies on several facets of ecosystem health simultaneously. Using indicators to predict grazing impacts is not a precise process. Evaluating and predicting the impacts of livestock on rangeland environments are complicated by unstable weather patterns, vegetation changes, wildlife interactions and, in many cases, soil types that vary in a single grazing management unit. Moreover, some indicators such as litter and annual production may be more important than other indicators such as non-native annual grass cover which can dominate a rangeland cover type regardless of the grazing strategy. A single indicator such as vernal pool habitat, a sensitive wildlife species or a specific noxious weed may not be important unless it exceeds, or fails to achieve an established level.
Managers can use the indicators presented here to measure progress towards the objectives established during planning, and can evaluate multiple impacts related to livestock grazing.