Table 2 . --Average fuel properties of the slash according to species and size class 



Fuel 



property 



Needles 



Ponderosa pine 



Douglas-fir 



0-1 



1-3 



3-5 



0-1 



1-3 



3-5 



Low heat valuei/ 



(B.t.u./lb.) 8,826 



Silica-free ashi./ 

 (fraction of dry 

 weight) .0155 



Total ashi-/ 



(fraction of dry 



weight) .0387 



Particle density 



(lb. /ft. 3) 31.8 



^(ft.2/ft.3) 1,756 



Proportion of total 



loading (percent) 22 



am. 



9,274 



.0123 



.0155 



35.6 

 156 



cm. 



8,885 



.0086 



.0096 



33.0 

 73.5 



43 



cm. 



8,885 



.0086 



.0096 



30.8 

 32.9 



28 



am. 



am. am. 



;,898 8,691 8,691 



0145 .0097 .0097 



,0166 



^/34, 



393 



3/27 



0108 



34 . 8 



80.7 



.0108 



32.3 

 29.6 



347 



^ Branchwood for the 1-3 and 3-5 cm. size classes was combined for the chemical 

 analyses . 



^Density values for the 0-1 and 1-3 cm. size classes were not significantly differ- 

 ent using a Tukey test at the 0.05 confidence level. 



^These values were not used to determine loadings for the spread calculations. 

 Instead, loadings by size class were sampled for each plot. 



12 r 



O 

 0) 



O 

 © 

 O 



0) 

 u 



Q- 



Figure 4. — Comparison 

 between observed and 

 predicted rates of 

 spread for all plots. 



ine 



Legend 



Ponderosa Pine (15 T/A) 

 Ponderosa Pine (30 T/A) 

 Douglas Fir (15 T/A) 

 Douglas Fir (30 T/A) 



2 4 6 8 10 



Observed rate of spread (ft./min.) 



12 



