8G JOURNAL Ol' FOKKSTRV 



spruce for the fourth and fifth decade from 440 to 700 trees, and in 

 one plantation in the fifth decade to 275 per acre ; in one plantation 

 670 to 710, in another 275 to 280 for pine in the same decade. 



A Japanese larch plantation became measurable in the eighth year, 

 and from the eighth to twelfth year, with 880 reduced to 860 stems, 

 grew at a rate of over 12 per cent, the current increment in the twelfth 

 year being 1 83 cubic feet and with no sign of decline, the average diam- 

 eter being 5.9 inches and the mean annual increment 132 cubic feet. 

 The other plantations being over 32 years old, no comparison is to be 

 made with the larch performance. 



For tlie spruce, in the better stands of over 35 to 47 years old, tlie 

 mean annual increment moves between 71 and 78, the current incre- 

 ment from 79 to 116 cubic feet, the diameters in the oldest and best 

 reaching over 11 inches. In no case is the maximum reached (when 

 current equals mean increment). 



The two Scotch pine plantations, from 37 to 47 years old, are evi- 

 dently poor, the better of the two showing for the last 7 years a con- 

 stant mean increment of 40 cubic feet and a vacillating current incre- 

 ment in the latter period of 50 to 51 cubic feet. 



The best performance in the other plantation, in the forty-fourth 

 year, shows a current increment of 71 cubic feet and a mean of 36 

 cubic feet. 



Most interesting it is to follow the movement of the increment per 

 cent, which with almost precise regularity is a function of time that 

 is sinking with age, due, of course, to the fact that the capital — the 

 growing stock — to which the increment is related is constantly increas- 

 ing. Thus the highest increment per cent is found in a spruce planta- 

 tion of 32 years with 6.95, the lowest with 2.44 at 44 years. The pine 

 plantations show the highest percentage at 38 years with 4.75 per cent, 

 the lowest with 2.45 per cent at 47 years. 



The author adds : At a moderate estimate it should be possible to 

 increase these results by 20 per cent, which would represent a yield 

 very substantially beyond what is looked for at the present time in 

 continental forests. 



Regarding the seasonal growth, this proves variable in different sea- 

 sons. A table shows for the different plantations the percentage of 

 growth made during each month of the growing season. The averages 

 for all species are : 



