32 



BULLETIN 544. U. S. DEPARTMENT OF AGRICULTURE. 



There is little doubt that Norway spruce makes a better height 

 growth in early life than our native spruce. It is well to remember, 

 however, in making comparisons in this particular instance, that the 

 two grow under entirely different sets of conditions. While the 

 native spruce has developed from seed under the keenest possible 

 competitive conditions, the Norway stock was in all likelihood nur- 

 sery grown, so spaced when planted as to eliminate undesirable com- 

 petition during early life, and possibly even cultivated. Then, too, 

 such plantations in general have been made on a rather better soil 

 even than that on which the average first quality red spruce stands 

 arc found. 



A comparison of the height growth of spruce seedlings in the forest 

 and in the open is shown in Table 7. 



Table 7. — Height growth of spruce seedlings. 



Age. 



Height. 









In the 



In the 





forest. 1 



open. 2 



Years. 



Feet. 



Feet. 



5 



0.3 



0.8 



10 



0.7 



2.4 



15 



i.l 



6.0 



20 



1.5 



10.0 



25 



2.0 



16.0 



30 



2.0 



28. 



35 



3.3 



35.0 



40 



4.1 





45 



5.0 









- 



1 Based on 615 trees. Data collected by It. S. Hosmer, 1901, on the New York State Forest Reserve. 



2 From p. 50, "Forest Conditions of Northern New Hampshire," Bulletin 55, Bureau of Forestry, 

 U. S. Dept. of Agriculture. 



The column of height in the open is entirely conservative, as will be 

 noted by comparing it with Table 5. 



DIAMETER GROWTH. 



The growth in diameter of spruce in virgin and other selection-form 

 forests is, like the height, largely independent of age. The relation 

 between diameter and age, however, can more readily be established 

 than that between height and age, since merely from a stump analysis 

 results closely approximating the truth can be obtained. 



