THE WHITE PINE REGION 



321 



If an uneven-aged white pine forest is wanted for some special 

 purpose, such for example as the aesthetic effect, it can be 

 secured by use of the selection system. White pine responds 

 well to this method of treatment. The timber secured is apt to 

 be larger in diameter for the same age, but more knotty than 

 that grown in even-aged stands. 



Thinnings at regular intervals should be made where the 

 stand is handled as an even-aged one. The thinnings can often 

 be started as early as the twentieth year and be repeated at 

 intervals of ten years or less. These thinnings, while having as 

 their primary object the better development of the trees left 

 standing, will yield substantial returns. The following table, 

 showing yields from thinnings, has been compiled from figures 

 secured in New Hampshire and Massachusetts, and published 

 in the " Report of the New Hampshire Forestry Commission for 

 1 905- 1 906," and in "Forest Mensuration of the White Pine in 

 Massachusetts." 



YIELD PER ACRE FROM THINNINGS IN THE PURE WHITE 

 PINE TYPE IN STANDS NEVER THINNED BEFORE. 



25 

 30 

 35 

 40 

 45 

 50 

 55 



Massachusetts. 



New Hamp- 

 shire. 



Feet, board measure. 



1,400 

 3.700 

 4-950 

 6,000 

 6,800 

 7,400 

 7,900 



750 

 3.300 

 5,600 

 7.500 

 8,900 

 9,900 



Trees less than 

 5 inches in 

 diameter. 



New Hamp- 

 shire. 



750 

 600 

 450 

 300 

 150 



It is believed that for stands under thirty-five years the 

 Massachusetts figures are best, and for stands over thirty-five 

 years the New Hampshire figures are more desirable. The 

 severity of the thinning has of course much to do with its yield. 



The figures of yield given above are true only for the first 

 thinning in stands not previously thinned. They do not show 



