PLANTING THE FOREST 45 



est ; and in considering it we must not forget that we must 

 so plant that each tree will be crowded and forced to grow 

 into valuable lumber; and this involves the mingling or 

 segregation of species, as the case may be, the distance 

 apart the trees should be planted, whether alone or mixed, 

 and also such subsequent treatment as will cause them to 

 continue the struggle and yet make the most rapid growth 

 possible. 



Unfortunately professional foresters are by no means 

 agreed upon the best course to pursue. The claim put forth 

 by those who advocate mingling the species, and planting 

 tolerant 1 with intolerant ones, is based upon the fact that 

 Nature mingles them in virgin forests, and that when a 

 forest is destroyed by the axe of the lumberman or in any 

 other way, she makes no discrimination either in species or 

 toleration, but again plants them haphazard. It is also in- 

 sisted that there may be a greater yield in a mixed forest of 

 tolerant and intolerant trees than in a forest of one sort alone, 

 because the tolerant ones can and do grow in the shade of the 

 intolerants, and thus the ground can be made to produce a 

 greater yield; and there is no doubt but that in naturally 

 planted forests this is true. Beyond this it is argued that 

 by mingling tolerant and intolerant trees a better shading 

 of the ground can be brought about because the open crowns 

 of the intolerant ones do not always afford a complete pro- 

 tection to the forest floor ; and, finally, that a mixed forest 

 is not so liable to be destroyed by insects or disease, or in- 

 jured by winds, as where only one species is present. 



Those who oppose mixing conifers with broadleaf trees, 

 or planting tolerant with intolerant ones of either class, 

 insist that the mingling of all in our virgin forests is a mat- 

 ter of accident instead of law or design ; that Nature has 

 made ample provisions for sowing seeds of all kinds of 

 trees through the agency of the winds or animals, and that 



1 As noted on page 35, a tolerant tree is one which can endure more or 

 lesa shade and an intolerant one such as exacts the fullest light ; that is, one 

 is shade-enduring and the other light-demanding. 



