SIL VI CULTURAL MANAGEMENT OF BLACK SPRUCE IN MINNESOTA 57 



Studies made in Canada (14, 15) have shown that balsam fir and 

 spruce pulpwood can be separated with reasonable accuracy on the 

 basis of the following characteristics : 



1. Resin ducts. — Spruce wood contains resin ducts that can be seen with a 

 hand lens on a freshly cut end surface. Sometimes exudations of resin are 

 visible on the ends of bolts. Balsam fir has no resin ducts. 



2. Knots. — Spruce knots usually do not tend to be nodal in arrangement. 

 Balsam fir knots are likely to be arranged in whorls. There is no swelling at 

 the base of spruce knots but some occurs in balsam fir. 



3. Grain. — In spruce the grain, as shown by drying checks, tends to be spiral. 

 In balsam fir it usually is straight. 



Black spruce bolts tend to be smaller on the average than white 

 spruce bolts (14) • Black spruce usually has narrower annual growth 

 rings. The wood is also said to be somewhat harder than the wood 

 of white spruce. 



Stand and Volume Tables 



Table 12 shows the distribution of trees by diameter and crown 

 classes in fully stocked stands of black spruce. It can be used for 

 calculating yields above different minimum tree sizes than those shown 

 in table 8. 



Table 13 gives volume of unpeeled wood and table 14 gives volume 

 of peeled wood in cords. 



