Char height

n. The vertical height on a section of a tree bole that has been scorched, burned, or reduced to charcoal.


  • Discussion


Char is a general term referring to an object that has been blackened by fire, and char height refers to the vertical distance from groundline to the highest point of blackening on a tree bole.  It is usually highest on the uphill side of the tree or the opposite side from the direction of maximum spread. The degree of charring may change along this distance. Char is usually deepest near the groundline and becomes lighter higher up.




Several studies have shown char height, or relative char height, to be correlated with post-fire tree mortality (see Dixon and others 1984; Wyant and others 1986; Regelbrugge and Conard 1993; Beverly and Martell 2003; Hély and others 2003; Thies and others 2006). Relative char height is the maximum char height as a proportion of the total tree height.



  • Units


    Preferred units for char height are m in technical reports and papers. Fire Management in the United States still uses the English units ft. See the following char height  units conversion table for conversion factors.


  • See Also

  • References

    • Beverly, J. L.; Martell, D. L. 2003. Modeling Pinus strobus mortality following prescribed fire in Quetico Provincial Park, northwestern Ontario. Canadian Journal of Forest Research. 33: 740-751.

    • Dixon, W. N.; Corneil, J. A.; Wilkinson, R. C.; Foltz, J. L. 1984. Using stem char to predict mortality and insect infestation of fire-damaged slash pines. Southern Journal of Applied Forestry. 8(2): 85-88.

    • Hély, C.; Flannigan, M.; Bergeron, Y. 2003. Modeling tree mortality following wildfire in the southeastern Canadian mixed-wood boreal forest. Forest Science. 49: 566-576.

    • Regelbrugge, J. C.; Conard, S. G. 1993. Modeling tree mortality following wildfire in Pinus ponderosa forests in the Central Sierra Nevada of California. International Journal of Wildland Fire. 3: 139-143.

    • Thies, W. G.; Westlind, D. J.; Loewen, M.; Brenner, G. 2006. Prediction of delayed mortality of fire-damaged ponderosa pine following prescribed fires in eastern Oregon, USA. International Journal of Wildland Fire. 15: 19-29.

    • Wyant, J. G.; Omi, P. N.; Laven, R. D. 1986. Fire induced tree mortality in a Colorado ponderosa pine/Douglas-fir stand. Forest Science. 32: 49-59.


  • Notes

    • Author 

      Sharon Hood, Forester

      Rocky Mountain Research Station