170 



Forestry Quarterly. 



VOLUME GROWTH OF RED PINE. 



The following is an attempt to determine the growth rate per 

 cent. : From the complete stem analysis of 45 trees ranging in 

 size from 72 to 18.1 inches in diameter, 4^ feet from the 

 ground, it was found that the total present volume of wood in- 

 side the bark is 1,213.28 cubic feet for all the trees. Twenty 

 years ago it was found to be 782.30 cubic feet and forty years 

 ago 564.44 cubic feet. The trees were chosen so as to represent 

 properly the different size classes in the stand. Calculating on 

 a simple interest basis, these figures show that during the last 

 twenty years the wood capital increased 55.1 per cent., which 

 averages 2.75 per cent. ; and during the last forty years 2.87 per 

 cent, per annum; or 2.218 and 1.93 compound interest respect- 

 ively. 



Another way of computing the percentage rate of growth dur- 

 ing the last twenty and forty years would be to figure out the 

 board contents of the trees at the present time and what it was 



