4 NORTHERN SPRUCE TYPE 



Mountains and the recently cutover and bvirnt slopes of Mt. 

 Mitchell in North Carolina. 



OPTIMUM GROWTH IN loo YEARS 



Diameter 



Height 



Density 



Yield per acre 



Spruce 



Balsam 



Paper birch. 



Inches 



lO 



II 



Feet 

 70 

 83 



Trees 

 41S 



Board feet 

 7400 



SSOO 



This table shows the optimum diameter and height growth for 

 the important species in this t3^e on a rotation of 100 years. The 

 density and yield per acre are also given. From these it is 

 evident that the short growing season is not favorable to rapid 

 diameter and height growth and that the stands per acre are 

 only heavy by reason of the great density of the trees. There is 

 a marked difference between the northern spruce and southern 

 Appalachian spruce. The latter grows faster in diameter and 

 height but the trees do not stand so close together. Generally 

 speaking the most profitable rotation for this type is at least 

 125 years. 



Timber Valuation. — There are several factors which make 

 estimating in the spruce type comparatively easy. The tracts 

 are usually large so that boundary difficulties are not serious. 

 Furthermore, the stands are uniform, the species few and damage 

 sUght. On the other hand the tracts are usually inaccessible so 

 that the cost of subsisting an estimating party is high. Supphes 

 frequently have to be brought in on men's backs because horses 

 carmot be used ofif the roads. Even these are in many cases 

 impracticable for hauling except when covered with snow. 

 Another obstacle to cheap work is the roughness of the mountain 

 slopes upon which the spruce grows and the density of the under- 

 growth. As a consequence an average day's work in this type 

 is 24 strip acres — i chain (66 feet) wide and 240 chains long. 

 However, only a small percentage of the tract need be actually 

 covered in this way. Only on very small tracts is more than a 



