Mean fire interval [Mean fire-free interval]

n.  An arithmetical index of fire frequency, expressed as the average number of fire intervals within a given time period.


  • Discussion


Although the median value is typically a more accurate measure of central tendency, the mean is also useful, particularly when only two fire intervals are available for analysis.  Because that situation occurs relatively frequently when sampling fire history, the mean fire interval (MFI) statistic has been used more often than the median fire interval.  However, the potential utility of the MFI statistic is diminished if only few data are available for analysis, or, when the fire intervals are highly variable. For further discussion, see Agee (1993), McPherson and others (1990), and Romme (1980).


  • See Also

  • References

    • Agee, James K. 1993. Fire Ecology of Pacific Northwest Forests. Washington, D.C.: Island Press. 490 p.

    • McPherson, G.R., Wade, D.D.; Philipps, C.B. 1990. Glossary of wildland fire management terms used in the United States. Washington, D.C.: Society of American Foresters.

    • Romme, William. 1980. Fire history terminology: report of the ad hoc committee. In: Stokes, Marvin A; Dieterich,  John H., tech. coords.  Proceedings of the Fire History Workshop, 1980 Oct. 20-24; University of Arizona, Tucson, AZ.  Gen. Tech. Rep. RM-81.  Fort Collins, CO:  U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 135-137.


  • Notes

    • Author 

      Steve Barrett, Consulting Fire Ecologist