THE EED SPRUCE. 



31 



which gain positions in the main crown cover start at about the 

 same time and develop with very little interruption. Their height 

 and age may consequently be easily correlated. The following table 

 shows the average height of the dominant and intermediate trees 

 comprising even-aged second-growth spruce stands of different ages 

 and on sites of different quality, measured in Maine, New Hampshire, 

 and Vermont in the fall of 1910. 



Table 5. — Height growth of spruce in even-aged, old pasture stands in Maine, New 

 Hampshire, and Vermont according to age and site qualities. 



[Average height of all dominant (including codominant) and intermediate trees in stands of different ages.] 



[CURVED.] 



Age. 



Site qualities. 



Basis. 



I. 



II. 



III. 



Years. 



20 



25 



30 



35 



40 



45 



50 



55 



60 



65 



70 



75 



80 



85 



90 



95 



100 



Feet. 

 24 

 31 

 36 

 42 

 46 

 51 

 55 

 58 

 61 

 64 

 66 

 68 

 70 

 72 

 73 

 74 

 76 



Feet. 

 19 

 25 

 31 

 36 

 40 

 44 

 47 

 50 

 53 

 55 

 57 

 59 

 61 

 63 

 64 

 65 

 66 



Feet. 

 14 

 20 

 25 

 30 

 34 

 37 

 40 

 42 

 45 

 47 

 49 

 50 

 52 

 53 

 55 

 56 

 57 



Sample 

 plots. 



1 



1 



1 

 6 

 6 

 8 

 16 

 14 

 4 

 1 





1 





59 



From sample plot data collected in 1910. 



For purposes of comparison the growth in height of Norway spruce 

 is given in Table 6. 



Table 6. — Height growth of Norway spruce. 1 





Average 



Age. 



height of 





stand. 



Years. 



Feet. 



5 



8 



10 



16 



15 



24 



20 



32 



25 



39 



30 



45 



35 



50 



40 



54 



45 



58 



50 



61 



55 



64 



60 



66 



1 Based on all measurements of all trees in 11 plantations (8 Quality I and 3 Quality II) 24-55 years old 

 (cur ed), made by Messrs. Tillotson, Barrows, and Williamson, of the Forest Ser\ice, in 1911, in Rhode 

 Island, Connecticut, Illinois, and Iowa. 



