CaiKulidii Forcstrij Journal, Jiilti, liH'. 



1185 



Making Use of Aspen Poplar 



By Dr. B. E. Fernow 



Dean, Facullij of Forestry, Univ. of Toronto 



Present and Potential Ways of Utilizing 

 Canada's Enormous Poplar Supplies 



THE most ubiquitous tree in 

 Canada is the Aspen poplar, 

 also called quaking aspen and 

 popple, there being two species 

 {Populus tremuloid and grandidcntata) 

 which are, however, in looks, 

 characteristics, and behavior so 

 much alike, that they need not, 

 for practical purposes, be distin- 

 guished. 



Not only is the aspen ubiqui- 

 tous, i.e. found everywhere and 

 in all kinds of situations from 

 East to West, but, at least east 

 of the Rocky Mountains it cov- 

 ers, we may assert, the largest 

 area of any tree species and 

 presents, perhaps, the largest 

 volume of wood material of any 

 one kind. This wide distribu- 

 tion gives to the aspen an econ- 

 omic importance which its wood 

 quality would otherwise not im- 

 part to it. 



Its ubiquitousness is explained by 

 the fact that it is an early and most 

 prolific producer of light feathery 

 seeds, which can be wafted by the 

 winds in all directions for miles, 

 sprouts quickly and grows cjuickly 

 in full sunlight. In spite of these 

 advantages in prolific seed produc- 

 tion, ease of dissemination, and rapid 

 growth, it would be a relatively rare 

 tree if it were not for the forest fires, 

 which create two conditions specially 

 favorable to aspen life, a seed bed of 

 mineral soil when the surface cover 

 of vegetable matter has been burned 

 off, and plenty of light. The aspen 

 is what the forester calls a most "in- 

 tolerant" species, i.e. intolerant of 

 shade: it is light-needing and in com- 

 petition with other, shadier species 



it soon succumbs; therefore, in the 

 virgin forest it is rare. 



The extent of aspen acreage is a 

 measure of the carelessness of the peo- 

 ple of Canada with fire, which by 

 killing competing, especially conifer- 

 ous, species and reducing the vege- 

 table soil cover, creates these favor- 

 able conditions for it. Wherever fire 

 has run through the loggers slash, 

 aspen quickly takes possession as 

 first comer; it is the balm for the 

 sores which the fire fiend inflicts. 



Protection for Conifers 



If seed trees of the coniferous kinds 

 are left, given long enough time, 

 these will re-establish themselves un- 

 der the light shade of the aspen, 

 which is advantageous to their de- 

 velopment, and by and by will over- 

 top and kill out the short-lived aspen. 

 While, then, the recovery of the 

 ground for the more valuable conifers 

 can in most cases be readily accom- 

 plished, there are conditions, as in 

 Manitoba, where dense shrub growth 

 of various kinds, notably hazel and 

 viburnum, comes in under the light 

 shade of the aspen and effectually 

 prevents the re-establishment of the 

 spruce. The aspen then becomes a 

 serious problem for the future re- 

 establishment of the conifer crop. 



For all these reasons the question 

 of the commercial use of the aspen is 

 an important economic problem. Here 

 we encounter a further trouble in the 

 fact that, before the aspen attains 

 what may be considered merchant- 

 able log size, it is liable to white or 

 black heart rot, the work of a fungus 

 entering some broken branch or dead 

 root and destroying the wood fiber, 

 progressing from inside outward. 



