Some Notes on Jack Pine. 3 



or is mixed with birch. With density reduced to 60% to 80% a 

 vigorous growth of herbaceous plants springs up, the most 

 common being Cornus canadensis, Lycopodiiim — several species ; 

 Aralia nudicaidis ; Clintonia borealis; Pteris aquilina; Lonicera 

 canadensis ; Ganltheria procumbens ; Unifolium canadense; 

 Smilacina trifolia; Chio genes hispidula; Coptis trifolia. 



The Forest. 



Jack Pine has adapted itself to many different sites and condi- 

 tions, but in general it is distingushed from the other pines by its 

 ease of reproduction and growth on sandy barren soils. It grows, 

 however, under varied conditions of moisture, from the pure 

 absolute muskeg with 70% to 80% water content to the bald rock 

 ridges where 5% water content is sometimes high in the heat of 

 the summer. 



However, it is only on the warm, granular, well drained, deep 

 soils of the upland that the Jack Pine grows to the sizes necessary 

 for tie-timber. "The optimum water content for its development 

 varies from 10% to 20%." Relatively dry coarse sand with 

 comparatively small amount of humus are typical sites. 



Given certain natural conditions it is possible to foretell with 

 fair accuracy the future forest cover of the region. Jack Pine 

 and Aspen will inevitably reclothe the bald burn and make their 

 appearance very soon after the fire has swept over the region, the 

 Jack Pine seeking the higher and drier sandy soils, while the 

 Aspen establishes itself on the richer loamy soils of the benches 

 and bordering on lakes. 



By the agency of fire the field of Jack Pine is being extended 

 throughout districts, where at one time White Pine reigned 

 supreme. 



At least two principal types of Jack Pine forest may be distin- 

 guished : 



Type i: — Jack Pine in mixture with White Birch and Black 

 Spruce on deep, well-drained soil, a mixture which produces the 

 largest returns in sizes suitable for cross-ties. 



