Loading of Fuel Complex 



Loading for the ponderosa pine forest floor litter averaged 324 grains per square 

 meter (2,890 lbs. /acre) and ranged between 129 and 601 grams per square meter (table 3). 

 These values compare with 630 grams per square meter for litter in natural red pine 

 (Pinus resinosa Ait.) stands and 380 grams per square meter for litter from jack pine 

 (Pinus banksiana Lamb.) plantations in the Lake States (Brown 1966). In Alabama, litter 

 in second-growth longleaf pine {Pinus palustris Mill.) stands ranged from 290 to 477 

 grams per square meter (Boyer and Fahnestock 1966) . 



The litter layers ranged from 1 to 3 centimeters in depth. The entire forest 

 floor (decomposed and undecomposed material together) averaged 5 centimeters in depth 

 and 2,623 grams per square meter (23,400 lbs. /acre). 



Loading for cheatgrass averaged 53 grams per square meter (470 lbs. /acre), as shown 

 in table 4. This average is not necessarily typical of cheatgrass production in 

 western Montana but is probably low, since little rain fell during the spring growing 

 season, which resulted in small yields. At Arrowrock, Idaho, cheatgrass yielded 42 

 grams per square meter (airdry) one year and 388 grams per square meter the next year 

 (Hull and Pechanec 1947) . This tenfold increase shows how production of cheatgrass can 

 vary from year to year. 



Table 4. -- Averages for fuel properties from a l-acre cheatgrass community 



Item 



Dense zone-' 



Moderate zone 



Sparse zone 



All plots-/ 



Number of plots 



11 



20 



7 



38 



Loading (g./m.^)^ 



77. 1 



53.2 



15.7 



53.1 



^(4.7) 



(6.1) 



(.7) 





A (cc./cm.2) 



6.98 



10.97 



25.47 



12.49 





(2.06) 



(4.72) 



(8.46) 





Particle spacing (cm.) 



1.22 



1.76 



2.29 



1.70 





(.15) 



(.58) 



(.30) 





Bulk density (g. /cm. 3)5/ 



4.42X10"'+ 



3. 16X10"'* 



1 .24X10"'* 



3.17X10"'* 





(.66X10"'*) 



(1.10X10"'*) 



(.45X10"'*) 







1010 



1590 



3690 



1810 





(30) 



(60) 



(100) 





^The zones were delineated on the ground according to visual inspection of density 

 of the cheatgrass . 



^Mean weighted by number of plots. 

 ^Ovendry basis. 



'*The numbers in parentheses are standard deviations. 



10 



