Site Conservation Rating

Site conservation ratings assess the capacity of the current vegetation community to protect against the decline in productive potential of a range site. Evaluations are determined by comparing the soil protection provided by the existing vegetation with the site conservation threshold. The site conservation threshold is judged to be the minimum vegetation needed to prevent accelerated soil erosion. Therefore, separate site conservation thresholds must be determined for each site, based on criteria related to soil protection, such as plant cover, biomass or density. A satisfactory site conservation rating is assigned when the protective criteria exceed the minimum level indicated by the site conservation threshold, otherwise an unsatisfactory rating is specified.

Proposed by a Task Group created by the Society for Range Management, the concept aims to develop a scheme to evaluate rangeland status that integrates both soil and vegetation factors. By contrast, current methods of range condition assessment are based exclusively on vegetation characteristics, even though soil degradation has a greater influence on site potential. The site conservation rating concedes that various different types of vegetation are possible on a site without compromising the prevention of accelerated soil erosion.

References and Further Reading

Task Group on Unity in Concepts and Terminology. 1995. New concepts for assessment of range condition. Journal of Range Management 48:271-282.

Watters, S.E., Weltz, M.A., and E.L. Smith. 1996. Evaluation of a site conservation rating system in southeastern Arizona. Journal of Range Management 49:277-284.