354 Forestry Quarterly. 



north and east slopes, the borders of White fir clumps, decayed 

 logs, etc-, are favorable. It is not the shade, in such cases, but 

 the surface moisture which is conserved by the shade or other 

 agent, that influences the seedling development. Dense plots 

 of seedlings, only a few inches in height are occasionally found 

 in full sunlight, but an examination will show that they have 

 started on the site of a decomposed log or other vegetable mat- 

 ter where surface moisture conditions were good. That seedlings 

 will not develop in the full shade of a high forest is shown by 

 the fact that there is little or no reproduction under the pure 

 stands of White fir. An interesting illustration of the demand 

 of White fir for surface moisture was noted in the Varney Creek 

 watershed. In this locality two small tracts were examined. 

 Both were on a very gentle north slope at an elevation of about 

 4,300 feet. On the first the old stand was a mixture of Yellow 

 pine and White fir. The soil was deep, loose and moist and 

 the ground cover mostly succulent plants and weeds. There was 

 very little brush of any kind. The reproduction consisted largely 

 of scattered White fir, although there were a few of the charac- 

 teristic clumps. The Yellow pine reproduction was limited to 

 the drier mounds and more open spots. On the second tract the 

 site and soil quality was exactly similar to the first. The old 

 stand was more open and consisted of Yellow pine with scatter- 

 ing White fir and Douglas fir. In this case the ground was 

 covered by good grass sod, and a few Amelanchier bushes. The 

 reproduction consisted almost entirely of Yellow pine seedlings 

 scattered thickly over the whole tract. The few White fir seed- 

 lings found were always in the shade of bushes or logs. So far as 

 conditions for White fir reproduction were concerned the two 

 tracts were identical except for the sod cover. The competition 

 of the grass roots for surface moisture evidently accounts for the 

 lack of White fir reproduction on the second tract. 



Susceptibility to Injury. \Vhite fir seedlings that are exposed 

 to fire are usually badly injured, but they possess an exceptionally 

 high degree of vitality and unless the stem is completely girdled 

 will ordinarily recover- Occasionally a seedling may be found 

 that has been girdled at the base. This is probably done in win- 

 ter by mice. The tops and upper branches of grown trees are 

 sometimes girdled by porcupines. Neither of the latter are of 



