CHAPTER I 

 NORTHERN SPRUCE TYPE 



General Conditions. — To this type of timberland belong the 

 North Woods of Maine, the upper slopes of the White Mountains, 

 the higher Green Mountains, the summits of the Adirondack and 

 Catskill Mountains, and the northern swampy parts of Michigan, 

 Wisconsin and Minnesota. Furthermore, a slender string of 

 isolated spruce-clad peaks extends southward along the backbone 

 of the Appalachian range and consequently some spruce is found 

 in Pennsylvania, West Virginia, Virginia, North Carolina and 

 Tennessee. The distribution of the type is shown graphically 

 on the accompanying map. 



Thruout its range spruce is most abimdant in a cool, moist 

 cUmate with long winters and heavy precipitation. Seldom is 

 the growing season more than four months long and the annual 

 precipitation must be at least 40 inches or supplemented by slow 

 drainage. This means that there is an abundance of moisture 

 available for tree growth because the long winters inhibit runoff 

 and the cool summers are unfavorable to rapid evaporation. 



These climatic conditions only occur on the steeper upper slopes 

 of mountains and in flat swamp land. On both sites the soil is 

 shallow but the spruce is well able to make the most of the scant 

 foothold with its flat, widely extended root system. Likewise 

 its conmion associates are trees of similar habit like the balsam, 

 paper birch and yeUow birch. However, by reason of its greater 

 adaptability to such untoward conditions, spruce tends to crowd 

 out its tompetitors and -form nearly pure stands if given time 

 enough. Hence the subtypes are generally transition types 

 caused by fire or cutting. The more imporant of these and their 

 composition by volume and niunber are: 



