NOTES ON JACK PINES AND SITKA SPRUCE. 151 



12 to 20 inches; on wet soils bordering swamps the mature tree 

 seldom reaches 60 feet. 



M. L. Fernald, in his paper on "The Lithological Factors 

 limiting the range of Jack pine and Thuya occidentalism states 

 that "Jack pine is confined exclusively to formations without 

 lime.'' He terms it " calciphobious." 



On the better classes of soil it associates with white pine, 

 birch, and aspen, and with red pine on deep dry sands deficient 

 in humus, and is normally found in dense stands after fire, 

 varying from 5 to 100 acres in area. Later, when the crowns 

 open up, balsam and spruce come in. The presence of birch 

 in the stand is a sure indication of good quality Jack pine. 



The tree is intolerant at all ages, therefore seedling growth is 

 rarely found under mature stands. It is said that the facility 

 of reproduction after fires, and the inability of reproduction 

 under mature stands means that Jack pine forests can in nature 

 only be secured by fire. Owing to the density of young stands 

 there is no ground vegetation, but later when the stand thins 

 out a strong growth of small plants comes up. The most 

 common are Vaccinum, Cornus canadensis, Lycopodium, Pteris 

 aquilina, Clintonia borealis, Lonicera canadensis, Gaultheria 

 procumbens, Smilacina procumbens, Aralia nudicaulis, etc. 



The stem has a moderate taper. Trees with much taper 

 indicate poor soil conditions ; full-boled trees are found only in 

 the deep, coarse, sandy plains which are its natural habitat. 

 Jack pine reaches its best development in the Great Lakes 

 region. The wood is light, soft, close-grained ; heartwood, light 

 brown ; sapwood, thick and nearly white. It is used mainly for 

 railway sleepers, posts, fuel, Kraft pulp, and sawn into lumber 

 for rough construction work. 



Lodgepole pine. — In the early days lodgepole pine received 

 its common name from the Indians, who used the tall, slender 

 young trees for their tepee poles. This species, though similar 

 to the eastern Jack pine, differs from it in some particulars. 

 The leaves are longer, being from 2 to 3 inches, and thicker on 

 the branches ; the bark is darker and thinner. Seedling growth 

 is rapid, and leaders have been measured from 2 to 3 feet in 

 length, but the average total growth is comparatively slow. 

 After fires in mature stands natural reproduction is too dense, 

 and as many as 300,000 one-year-old seedlings have been found 

 on one acre. In the Deer Lodge National Forest, U.S., stands 



