FORESTS OF BOCKY MOUNTAINS FOREST RESERVE 33 



TABLE 10. 



SPRUCE REPRODUCTION. 

 Seedlings per acre. Plots representing maximum conditions. 



None {Moist site ; sphagnum moss 2 inches and humus 3 inches thick. 



H j Dense stand with ground cover of dry litter. 



400 Art a burned in early spring ; no bare soil exposed. 



2,400 Compact moss ; humus 2 inches thick. 



5,600 Old burn ; little bare soil ; 1 inch to U inches, well decomposed humus. 



6,800 Lumbered area with favourable seed bed; 20 per cent of area covered with litter, 



rest with thin grass ; humus f inch thick. 

 Opening in virgin stand ; seed bed covered with thin moss and needles ; humus 



8,400 

 16,000 



2 inches thick, well decomposed. 

 Light fire leaving seed-trees and exposing considerable soiL 

 Road embankment ; soil moist and 50 per cent washed bare. 



In general, spruce is a tree to be very favourably considered, especially where 

 it already forms a part of stands which it is desired to reproduce by natural regenera- 

 tion. It attains a comparatively large size and produces useful lumber. It can 

 adapt itself to most sites. It has a favourable rate of growth which has the special 

 advantage of being accelerated whenever an increase in the space around the tree 

 gives a more favourable opportunity for development. Spruce seeds will germinate 

 under many natural conditions of seed-bed, and the seedlings will develop under the 

 shade of the older trees. The chief demerits of the species are its slow juvenile 

 development, even in full light, and its liability to wind-fall. 



LODGEPOLE PINT:. 



Locally, this is commonly called jack pine, but the true jack pine (Pinus Bank- 

 siana) does not enter the region under consideration. Lodgepole pine is the most 

 abundant tree of the region. In mature stands, it divides the area with spruce and 

 other species, but in the widespread second-growth stands it vastly predominates 

 and so holds a very important place in relation to the future. It ako has the dis- 

 tinction of producing the clearest and highest grade of lumber, although it is small 

 in size. This is due to the form of the tree which has a long cylindrical bole, well 

 cleaned of branches, and a small short crown induced by the intolerance of the species 

 and its habit of growing in dense, uniform, even-aged stands. The bark is very thin, 

 0-2 to 0-4 in. comparatively smooth, with small scales or shallow ridges, and greyish 

 in colour. The main roots descend diagonally into the ground and for supporting 

 purposes do not form a circle of more than four to five feet, and. although they are 

 well anchored by smaller roots, the tree on well-drained soils is little more wind- 

 firm than spruce. Its dense habit of growth forbids the exposing of single specimens 

 or small groups to the winds. The average maximum size is about 26 inches in 

 diameter at breast-height and 110 feet in height. In age it seldom reaches over 250 

 years, and after 125 years shows only slow growth. 



Atmospheric conditions affect it more readily than spruce, and the frequent 

 frosts at the higher elevations are undoubtedly a large factor in checking its growth 

 there. In Montana an extensive killing of foliage and even of entire trees was 

 observed as a result of severe and sudden alterations of ' Chinooks ' and cold waves, 

 which is illustrative of the sensitiveness of the tree, since other species for the most 

 part escaped apparent injury. Indications of a similar damage to this species in 

 Canada also have been noted. 



