506 Forestry Quarterly 



after careless cutting or because it has never been established, the 

 conifer stands are open, more scraggy and decadent, discouraging 

 seed production. In presence of birch, and especially where this 

 has suflficient nourishment to stand close, we find ths spruce already 

 considerably advanced toward the summit. Where the birch 

 from above and the spruce from below have grasped each other's 

 hand the pine is doomed. This union of spruce and birch takes 

 place first on shaded slopes and better sites, and on the more 

 friable formations ; slower on exposed slopes, shallow or rocky soil 

 and where the rock formation weathers slowly. It does not follow 

 that the pine yields as soon as the two competitors have effected a 

 union, but it is only a question of time until it is reduced to scattered 

 individuals tenaciously clinging to the drier knolls within a forest of 

 spruce and birch. Their tall clear boles and spreading crowns 

 telling of a subdued race ; subdued because conquerors are able to 

 improve the soil conditions and turn it to their own benefit, and by 

 dense thickets prevent pine reproduction. 



The natural tendency of the spruce to creep toward the birch 

 and' timberline, crowding out the pine, is greatly accelerated by 

 opening the stands in logging. Pine forests are being culled 

 everywhere. These come up to birch and so close that they are 

 difficult to penetrate; and where these thickets appear some dis- 

 tance above the vanguard of the advancing spruce, the birch and 

 spruce union is effected much sooner than it would be if the pine 

 had remained. For the protection and nourishment furnished by 

 the birch leaf and litter and the increased amounts of shade and 

 moisture are factors greatly enhancing the stealthy progress of 

 spruce toward the upper slopes. 



In this war against the pine the moose and other game animals 

 assist, and even inorganic Nature, of which water plays an im- 

 portant part, is limiting the exterior boundaries of the pine type 

 both from above and below, partly by the formation of swamps 

 made by a rising water table after logging, in which the pine 

 flounders, while the spruce survives. 



In taking up the question of assistance to the pine, it must be 

 decided which tree, spruce or pine, best performs the duties imposed 

 upon a tree toward timberline. On these areas a coniferous forest 

 with birch cannot be as productive in the same sense as a forest on 

 the lower slopes. The great difference as far as productivity goes 

 lies in that the upper forest is most productive when left uncut. 



