SILVICULTURAL SYSTEMS 



23 



in leaving scattered trees or small groups, and to overcome this 

 difficulty large blocks of trees are reserved. The ideal way to 

 overcome this danger of windfall would be to use the strip sys- 

 tem described a Uttle farther on, which leaves 40 to 50 per cent 

 of the timber for a second cutting. Oftentimes poor market 

 conditions and expensive logging prevent two cuttings and 

 require that at least 75 per cent of the timber be cut in one cut- 

 ting. Under these circumstances the best which can be done is 



12 3 4 5 6 7 b 9 10 H 12 13 14 16 lb 17 18 19 20 21 22 23 24 25 2(> 27 



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Fig. 6. — The scattered seed-tree method. 

 A mature stand marked for a reproduction cutting. The entire stand is to be cut 



except for occasional seed trees. 

 Ten years later, showing the reproduction fully established and the old seed trees 



marked for removal. 



to leave 15 to 25 per cent of the timber in the form of large blocks. 

 These blocks are carefully located with reference to seeding the 

 cut-over area, usually on ridges or the upper portions of slopes. 

 A young stand should be selected for this purpose if practicable, 

 since it is not expected to return to remove it for a number of 

 years, possibly not for an entire rotation. Occasionally there 

 are blocks of inferior trees of little value for lumber which, never- 

 theless, are perfectly good for seed purposes. At best the method 



