Figure 4. — The metal frame 

 delineates a 1- foot-square 

 plot upon the forest floor 

 of ponderosa pine. Depth 

 of the L layer was measured 

 along perpendicular bisec- 

 tors of the plots at 

 locations marked "X. " 



Depth of fuel complex was measured as the distance from the ground to an average 

 height regarded as the general level across the top of the cheatgrass. Occasional 

 cheatgrass parts existing above what appeared as the general top level were excluded 

 from all measurements. All cheatgrass inside the 10- by 25-centimeter plots was care- 

 fully clipped, removed, and dissected into the six kinds of particles for determining 

 surface area and volume. The small amount of litter present (mostly fallen spikelets) 

 was excluded from measurements. 



VOLUME, SURFACE AREA, AND DENSITY MEASUREMENTS 



Volume and surface area of pine needles and cheatgrass were determined from volume- 

 per-gram and surface-per-gram factors multiplied by weight in grams of each type of 

 particle on each plot. These factors were determined from measurements of surface 

 area, volume, and weight for a subsample of particles collected from the study areas. 



Figure 5. — Cheatgrass ^ the pre- 

 dominant vegetation in this 

 area, averages 52 grams per 

 square meter (470 lbs . /acre) . 

 Other plant species visible 

 are balsamroot 



(Balsamorhi za sagittata Nutt.) , 

 moth mullein (Verbascum 

 blattaria L.), and daisy 



(Erigeron spp.) . ' ^P^"^' " ^"^'^ ' -^^^ 



■k 



