PHYSICAL-PROPERTIES OF WOODY FUEL-PARTICLES OF SIERRA-NEVADA CONIFERS

A study of the physical properties of Sierra Nevada conifer fuel parti cles showed that average diameter, squared quadratic mean diameter, su rface-area-to-volume ratio, and specific gravity varied significantly by species for all four timelag fuel diameter size classes. The nonhor izontal angle was not significantly affected by size class, and the de velopmental stage of the overstory did not affect any of the propertie s. These values are used to calculate fuel weight and predict fire beh avior. Regional variation in physical properties can result in fuel we ight estimates for the Sierra Nevada that differ from under 40.8 perce nt to over 8.3 percent from those calculated from Rocky Mountain value s. These differences made small changes in predicted fire behavior.