344 



George E. Nichols, 



vegetation, but most of the humus as well has been consumed. 

 In areas of this sort succession must start all over again from 

 near the bottom and a sequence of stages similar to what has 

 been described in primary successional series may be observed. 

 To be sure, succession in an area which has been denuded by 

 fire differs in certain respects from a primary succession, owing 

 chiefly to the fact that even repeated fires fail to completely 

 annihilate all the previously existing humus and plant life, and 



Figure 39. — White spruce reproduction in an area 

 repeatedly cut and burned ; South Bay, Ingonish. 



;hich has been 



that the relicts which have thus survived may play an important 

 part in the succession. But it is hardly worth while to attempt 

 to depict the stages in detail. In general it may be stated that, 

 just as in the case of primary successions, there is a marked 

 variation in the nature of the primitive associations, due to local 

 differences in the nature of the substratum, etc., but that all 

 successional series tend to merge in the formation of forest. 



Ahiindancc of ivhite spruce the result of fire and cidtivation. — • 

 At the present day, throughout the region of deciduous forests, 

 wherever tracts of land have been cultivated and then abandoned 



