THINNING AND PRUNING 125 



correct the errors of heavy thinning. In the case of pure 

 fir woods, his own opinion was that they should be thinned 

 regularly, although not to such an extent as hardwoods. 

 The thinning here, however, should begin when the trees 

 are at a height of 5 or 6 feet, and continue until they 

 have reached a height of 20 to 30 feet, and at the time 

 of planting ought to have been gradually so thinned that 

 the trees shall not stand nearer than 20 feet from each 

 other, if common Scotch, spruce, or silver firs. 



Sang deals with the thinning of plantations under two 

 heads mixed plantations and fir plantations. The least 

 valuable and the least thriving plants should first be taken 

 out in the case of mixed plantations. In no case are the 

 nurses to be suffered to overtop or whip the plants intended 

 for a timber crop, and in bleak situations it is better to 

 prune off the branches from one side than to remove the 

 whole tree from the side of the more valuable species. 

 Nurses such as larch should be retained in a certain 

 proportion throughout the life of the plantation, but, when 

 consisting of mountain ash or Scots fir, they should all be 

 removed by the time that the plantation arrives at the 

 height of 15 to 20 feet. The final distance apart at 

 which the permanent trees should stand Sang puts at 

 25 to 30 feet, according to their kinds and manner of 

 growth. Plantations of Scots fir, if the plants have been 

 put in at 3 or 3J feet apart, will require little care until 

 the trees are 10 or 12 feet high, and at forty years of 

 age a good medium distance for the trees may be about 

 15 feet every way. After a certain period, perhaps by 

 the time the plantation arrives at the age of fifty or 

 sixty years, it should be thinned more freely in order to 

 harden the timber. 



Brown, in The Forester, gives a number of directions for 

 thinning both mixed and fir plantations, which agree gener- 

 ally with the authors mentioned above. He draws attention 

 to the fact that many foresters aim at giving a plantation 

 a regular appearance, while leaving the trees as nearly as 

 possible at a given distance from one another, without taking 

 into consideration the ultimate welfare of the plantation. 

 Brown, however, points out that the proper object should be 



