210 THE PRINCIPLES OE HANDLING WOODLANDS 



the end of the rotation.'^ He estimates that the aggre- 

 gate yield of the thinnings and the accretion cuttings 

 will be about equal to the \'olume of the final cuttings, 

 and that the latter will be fully equal to the final cut- 

 tings under other methods of treatment. 



This program is somewhat more drastic than that 

 recommended b\' some other European foresters. It ma\- 

 be compared with that of Dr. Flury, whose proposals are 

 the result of a series of experiments in stands subjected 

 to different grades of thinning. 



Dr. Fiurv's conclusions for the management of spruce 

 are that the thinnings should begin early and be con- 

 ducted regularly. During \outh and up to about middle 

 age — 50 to 60 vears — the\' should be between grade B 

 and C, approaching C. After middle age they are in- 

 creased to a full C grade. At the beginning of the last 

 third of the rotation, the stand is in a condition to 

 require no more real thinnings. FVom that time further 

 openings would be of the character of accretion cuttings. 

 He recommends an early beginning of reproduction 

 cuttings under the sheltervvood system and a long pe- 

 riod during which the trees would grow rapidly in an 

 isolated position, with the ground protected bv the \'oung 

 crop. This plan dilTers from that of Dr. Mayr chieflv 

 in extending the period of real thinnings, and thus 

 holding the stand dense for a longer time. 



The French Method. — Somewhat in contrast to the 

 principles just described, is a method of thinnings used 

 very extensively in France 



