Duff load

n. The mass per area unit of the duff layer.

 

  • Discussion

 

Duff loads for a range of vegetation types are reported in the Stereo Photo Series for Quantifying Natural Fuels, volumes I to VI (Ottmar and others 1998a, 1998b, 2000a, 2000b, 2000c, 2002a, 2002b, 2003).  A summary of duff bulk density  values for a range of forest types is available in Brown and others (1982) and Barney and others (1981). Duff load can be calculated as either the product of duff bulk density and duff depth or estimated by drying and weighing duff samples from fixed area plots.

 

  • Units

     

    Preferred units for duff load are kg/m2 in technical reports and papers. Fire Management in the United States still uses the English units t/ac. See the following duff load  units conversion table for conversion factors.

     

  • See Also

  • References

    • Barney Richard J.; Bevins, Collin D.; Bradshaw, Larry S. Forest Floor Fuel Loads and Bulk Densities in Four Alaskan Cover Types.  Gen. Tech. Rep. INT-129. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 7 p.

    • Brown, James K.; Oberheu, Rick D.; Johnston, Cameron M. 1982. Handbook for inventorying surface fuels and biomass in the interior West. Gen. Tech. Rep. INT-129. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Stations. 48 p.

    • Ottmar, Roger D.; Vihnanek, Robert E. 1998a. Stereo photo series for quantifying natural fuels: volume II: Black spruce and white spruce types in Alaska. PMS 831. NFES 2580. Boise, Idaho: National Wildfire Coordinating Group, National Interagency Fire Center. 65 p.

    • Ottmar, Roger D.; Vihnanek, Robert E; Wright, Clint S. 1998b. Stereo photo series for quantifying natural fuels: volume I: Mixed-conifer with mortality, western juniper, sagebrush, and grassland types in the interior Pacific Northwest. PMS 830. NFES 2580. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 73 p.

    • Ottmar, Roger D.; Vihnanek, Robert E. 1999. Stereo photo series for quantifying natural fuels. Volume V: midwest red and white pine, northern tallgrass prairie, and mixed oak types in the Central and Lake States. PMS 834. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 99 p.

    • Ottmar, Roger D.; Vihnanek, Robert E.; Wright, Clinton S. 2000a. Stereo photo series for quantifying natural fuels. Volume III: Lodgepole pine, quaking aspen, and gambel oak types in the Rocky Mountains. PMS 832. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 85 p.

    •  Ottmar, Roger D.; Vihnanek, Robert E. 2000b. Stereo photo series for quantifying natural fuels. Volume VI: Longleaf pine, pocosin, and marshgrass in the Southeast United States. PMS 835. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 85 p.

    • Ottmar, Roger D.; Vihnanek, Robert E.; Regelbrugge, Jon C. 2000c. Stereo photo series for quantifying natural fuels. Volume IV: pinyon-juniper, sagebrush, and chaparral types in the Southwestern United States. PMS 833. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 97 p.

    • Ottmar, Roger D.; Vihnanek, Robert E. 2002a. Stereo photo series for quantifying natural fuels: Volume IIa: hardwoods with spruce in Alaska. PMS 836. NFES 2668. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 41p.

    • Ottmar, Roger D.; Vihnanek, Robert E; Wright, Clint S. 2002b. Stereo photo series for quantifying natural fuels: volume Va: Jack pine in the Lake States. PMS 837. NFES 2669. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 49 p.

    • Ottmar, Roger D.; Vihnanek, Robert E.; Mathey, Jared W. 2003. Stereo photo series for quantifying natural fuels. Volume VIa: sand hill, sand pine scrub, and hardwoods with white pine types in the Southeast United States with supplemental sites for volume VI. PMS 838. Boise, ID: National Wildfire Coordinating Group, National Interagency Fire Center. 78 p.

     

  • Notes

    • Author 

      Jim Reardon, Physical Science Technician

      Rocky Mountain Research Station