24 Forest Club Annual 



COMPOSITE TYPE. 



A slight change of aspect to a more easterly or northerly 

 exposure, with a slight increase in elevation, will bring about 

 the conditions necessary to change a pure stand of Western 

 Yellow Pine to a composite type, by increasing the amount of 

 Douglas Fir and proportionally decreasing the amount of West- 

 ern Yellow Pine. This type should be regarded as a transition 

 type between pure Western Yellcw ^ine and a mixture of 

 JJouglas Fir and White Fir. 



This type normally requires a soil which is moister and more 

 loamy than that necessary for the Western Yellow Pine. The 

 increased density of the stand restricts the rank growth of grass, 

 which is so characteristic of the Western Yellow Pine type. 

 Although these conditions very largely eliminate the grass factor 

 in the spreading of fire, they increase the amount and complexity 

 of the underbrush. At the same time the amount of litter is 

 increased because of the increased density of the stand, as well 

 as the consequent restriction of the sun's rays which retards 

 the decomposition of the litter. This increased stand density 

 with the greater amount of underbrush, reproduction and litter 

 makes it apparent why the danger and severity of fires increases 

 verv materially. 



Surface fires are exceptionally destructive to reproduction 

 in this type because it is mixed with underbrush and surround- 

 ed by litter. Very often poles and standards will be in a fairly 

 vigorous state of growth after a fire, merely having had 

 their bark scorched, while the entire stand of young reproduction 

 will have been killed. The methods used in fighting fires in this 

 type are very similar to those advocate for fires in the Western 

 Yellow Pine type. Fire lines are more necessary because of the 

 density of the stand. 



FIR TYPE. 



In this type Western Yellow Pine occurs only as an invader. 

 while Douglas Fir and White Fir are the predominating species. 

 The relative proportion of each of these species in the type 

 depends entirely upon the moisture conditions of the site. Where 

 it is very moist and cool, the White Fir is decidedly the predo- 

 minating species and sometimes excludes Douglas Fir entirely. 

 As the slope changes to a more southerly or westerly exposure, 

 the soil becomes dryer and the fir type gradually merges into 

 the composite type. The White Fir gives way to the Douglas 

 Fir on the dryer soils and this species in turn gives way to West- 

 ern Yellow Pine on still dryer soils. 





