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Key Species Method

Description and Uses

The Key Species Method is a combination of the Landscape Appearance Method and the Ocular Estimate Method. This method bases utilization levels on an ocular estimate of the amount of forage removed by weight on individual key species with observations recorded in one of seven utilization classes. It was developed to be used in areas where perennial grasses, forbs, and/or browse plants are the key species.

Advantages and Limitations

The Key Species method is rapid since the estimated percentage of forage removed is recorded in one of seven broad classes rather than as an exact percentage. It can be reasonably accurate, assuming the observers are well trained since different observers are more likely to estimate utilization in the same classes than to estimate the same utilization percentages. However, observer bias can be a concern. This can be reduced by limiting observations to individual plants or small areas (quadrats).

With this method there is no need to disturb the vegetation (i.e., harvesting).

Training and experience are important when conducting this method and exclosures, cages, or fenced areas are typically necessary for training purposes.


Technical and Application References

  • Schmutz, Ervin M. 1971. Estimation of range use with grazed-class photo guides. Coop. Extension Service and Agr. Exp. Sta., Univ. of Ariz., Tucson, AZ, Bull. A-73. 16 p.
  • Schmutz, E.M., G.A. Holt, and C.C. Michaels. 1963. Grazed class method of estimating forage utilization. Journal of Range Management. 16:54-60.

The following are sources of existing photo guides:

  • University of Arizona, Cooperative Extension Service and Agricultural

Experiment Station, Tucson Arizona 85721. Bulletin A-73.

  • University of Idaho, College of Forestry, Wildlife and Range Science,

Moscow, Idaho 83843. Station bulletin 54.

  • Montana State University. Forage Use - A Tool for Planning Range

Management. Extension Service. July 1988.

  • Kinney and Clary. 1994. A Photographic Utilization Guide for Key Riparian

Graminoids. USFS GTR-308.

Similar Approaches

Additional Information

field_methods/key_species_method.1230752529.txt.gz · Last modified: 2012/02/22 13:28 (external edit)