The bottoms of the sampling planes were delineated by the top of the forest floor 

 and the tops of the planes by the highest particle passing between the sides of the 

 planes. Depth of slash was measured to the nearest centimeter, but forest floor litter 

 was excluded from measurements. The vertical sampling planes were divided into strata 

 20 centimeters deep and the number of branch particles intersecting the planes recorded 

 by strata and the following particle diameter classes: 0-1, 1-3, 3-10, and over 10 cen- 

 timeters. Intersections by species were kept separate for the 0-1 size class. Particle 

 diameters appearing borderline between classes were checked with a go-no-go gage. 



Calculations 



Volume of branchwood was calculated from: 



V = L 



nd 2 ir 2 



where V = Volume, cm. 3 



L = Length of fuel complex perpendicular to sampling plane--set at 1 cm. 



n = Number of particle intercepts 

 d = Average diameter of size class, cm. 

 Derivation of the formulas and theory and application of the technique are discussed 



Derivation or tne formulas and tneory and appli< 

 further by Brown ,-2/ Beaufait and Van Wagner. 3 



Average diameter of the 0-1 centimeter size class was determined for a large sample 

 of branches randomly collected from the study area. Branch diameters were measured 

 every 10 centimeters beginning at a point 1 centimeter in diameter and continuing to 

 and including the tips of all branchlets. The average was weighted by distance between 

 measurements which was usually less than 10 centimeters for the tip measurements. 

 Average diameter for the 1-3 and 3-10 size classes was determined by running transects 

 through slash on all exposures and measuring diameters of all branches between 1 and 10 

 centimeters in diameter falling under the transect. Where pieces of slash over 10 centi- 

 meters in diameter intersected the sampling planes, they were measured individually and 

 handled separately in the volume equation; thus, determination of an average diameter 

 for these larger pieces was unnecessary. 



i J . K. Brown. A planar intersect method for sampling fuel volume and surface 

 area. Forest Sci. (in press). 



^W. R. Beaufait. Prescribed fire cooperative study--Region 1-INT. (Study Plan 



No. 2102-12 on file at Intermountain Forest $ Range Exp. Sta. , Northern Forest Fire 



Laboratory, USDA Forest Serv. , Missoula, Mont.) 1967. 



5 C. E. Van Wagner. The line intersect method in forest fuel sampling. Forest 



Sci. 14(1): 20-26, illus. 1968. 



3 



