r 



Figure 1. — This 80-year- 

 old open stand of 

 ponderosa pine, which 

 contained 220 trees per 

 acre and 110 square 

 feet of basal area, 

 averaged 221 grams 

 per square meter 

 (2,060 lbs. /acre) 

 of fuel in the 

 litter layer. 



through a wood frame that measured 1 by 4 inches on the bottom side. The end of the 

 rule was placed at the top of the F layer^ and the frame was lowered to what appeared 

 as the top of the L layer. Depth was recorded where the frame intersected the rule. 

 Occasional single needles sticking above the general level of the L layer were de- 

 pressed. Identification of the top of the F layer was fairly easy due to the bound 

 condition (resulting from fungal mycelium) of the F material. Depth of the L layer was 

 used to calculate the volume of the fuel complex for each plot. 



A metal frame, 1 foot square, was positioned over the plot and the number of 

 particles crossing under the frame was counted along two adjacent sides for calculation 

 of particle spacing (fig. 4). Particle orientation was ocularly estimated for a 

 minimum of 10 particles per side. The angle made by the intersection of a particle 

 with an imaginary extension of the bottom of the metal frame was judged as one of six 

 adjacent 30°-wide sectors. Orientation was recorded in the horizontal direction because 

 practically all particles lie in this direction due to the influence of gravity. This 



Figure 2. — This 60 -year- 

 old dense stand of 

 ponderosa pine, which 

 contained 2, 700 trees 

 per acre and 230 

 square feet of basal 

 area, averaged 415 

 grams per square 

 meter (3,680 lbs./ 

 acre) of fuel in the 

 litter layer. 



^Ibid. 



f3 



