IGNITION BEHAVIOR OF LIVE CALIFORNIA CHAPARRAL LEAVES

Abstract

Current forest fire models are largely empirical correlations based on data from beds of dead vegetation. Improvement in model capabilities is sought by developing models of the combustion of live fuels. A facility was developed to determine the combustion behavior of small samples of live fuels, consisting of a flat-flame burner on a moveable platform. Qualitative and quantitative combustion data are presented for representative samples of California chaparral: manzanita (Arctostaphylos parryana); oak (Quercus berberidifolia); ceanothus (Ceanothus crassifolius), and chamise (Adenostoma fasciculatum). Times to ignition were significantly influenced by shape effects, whereas ignition temperature was more dependent on chemical composition.

Keywords:

• wildland fires
• ignition

This research was funded by the USDA/USDI National Fire Plan administered through a Research Joint Venture Agreement (No. 01-CR-11272166–168) with the Forest Fire Laboratory, Pacific Southwest Research Station, USDA Forest Service, Riverside, CA. Special thanks go to Brett Butler at the Fire Sciences Laboratory, Rocky Mountain Research Station, USDA Forest Service, Missoula, MT, for advice and insight in developing this experiment. Thanks also to Joey Chong from the Forest Fire Laboratory, who helped with the infrared camera images.

Notes

¹Trade names are presented for information purposes only and do not constitute endorsement by the U.S. Department of Agriculture.

Note: These samples had moisture contents (wet/dry basis) of less than 10% and were all obtained in the horizontal leaf configuration.