10 BULLETIlSr 820, IT. S. DEPARTMENT OF AGRICULTURE. 



Table 1. — Rate of growth in diavieter and height of jack pine, in dense stands and of 

 isolated or nearly isolated trees, in Hubbard County, Minn. 



" 



Trees in dense stands 18 to 99 years old. 



Isolated or nearly iso- 

 lated trees 22 to 82 

 years old. 



Age. 



Average. 



Maximum. 



Average growth. 





D.b. h. 



Height. 



D. b. h. 



Height. 



D. b. h. 



Height. 



Years. 

 10 



lyiches. 

 1.2 

 2.3 

 3.3 

 4.0 

 4.6 

 5.1 

 5.6 

 6.1 

 6.5 

 6.9 

 7.3 

 7.6 

 8.0 

 8.3 

 8.7 



Feet. 



9 

 IG 

 22 

 28 

 33 

 38 

 42 

 45 

 48 

 51 

 54 

 57 

 59 

 62 

 64 



Inches. 

 1.8 

 3.8 

 5.5 

 6.9 

 7.9 

 8.8 

 9.5 

 10.2 

 10.9 

 11.5 

 12.1 

 12.7 

 13.3 

 13.9 

 14.5 



Feet. 

 19 

 25 

 33 

 38 

 42 

 46 

 50 

 53 

 56 

 59 

 62 

 65 

 68 

 70 

 72 



Inches. 

 1.7 

 3.5 

 5.1 

 6.6 

 7.9 

 9.1 

 10.2 

 11.1 

 11.8 

 12.5 

 13.1 

 13.7 

 14.2 

 14.8 

 15.3 



Feet. 



12 



15 



22 



20 



29 



25 



35 



30 



39 



35 



42 



40 



44 



45 



40 



53 



47 



55 



47 



CO 



48 



65 



49 



70 



40 





50 



8^ 



50 







Based on 604 trees, 18 to 99 years old. Measurements by H. H. Chapman. 



Table 1 indicates a much faster diameter growth of isolated and 

 partly isolated trees than the average growth of trees in dense 

 stands — faster even than the average growth of predominant trees in 

 such stands. 



Table 2. — Rate of grotvth in diameter and height of jack pine in Cass County, Minn. 





Average. 



Maximum. 



Age. 



Average. 



Maximum. 



Age. 



Diameter 





Diameter 





Diameter 





Diameter 







breast 



Height. 



breast 



Height. 





breast 



Height. 



breast 



Height. 





high. 





high. 







high. 





high. 





Years. 



Inches. 



Feet. 



Inches. 



Feet. 



Years. 



Inches. 



Feet. 



Inches. 



Feet. 



5 





3 



10 





12 

 20 



65 



70 



8.4 

 8.8 



63 

 65 



11.1 

 11.6 



72 



10 



0.6 



1.4 



74 



15 



1.5 



16 



2.8 



28 



75 



9.2 



68 



12.1 



76 



20 



2.4 



23 



4.1 



35 



80 



9.6 



70 



12.6 



78 



25 



3.3 



30 



5.3 



41 



85 



10.0 



71 



13.0 



80 



30 



4.2 



35 



6.3 



47 



90 



10.4 



73 



13.4 



82 



35 



5.0 



40 



7.2 



52 



95 



10.8 



74 



13.8 



83 



40 



5.7 



45 



8.1 



57 



100 



11.2 



75 



14.2 



85 



45 



6.3 



50 



8.8 



61 



105 



11.6 



76 



14.6 



86 



50 



6.9 



53 



9.5 



64 



110 



11.9 



77 



15.1 



88 



55 



7.4 



57 



10.1 



67 



115 



12.3 



78 



15.5 



89 



60 



7.9 



60 



10.6 



70 



120 



12.6 



79 



15.9 



90 



Eased on 52 trees 69 to 124, averaging 93 years old, and 7 to 16 inches in diameter, the trees having been 

 cut for saw logs. Measurements by J. St. J. Benedict. 



