368 JOURNAL OF FORESTRY 



rather surprising when compared with 220 years as given for cuhiii- 

 nation of yield in the sugar pine-yellow pine type. 



The rotation on which to cut sugar pine-yellow pine stands is 

 said to be determined by the highest rate of volume production, and 

 is placed at 180 years. The yield table figures for this type show a 

 mean annual growth at 180 years of only 122 board feet per acre, 

 while at 220 years this has risen to 130.5 board feet per acre. Thus, 

 unless some other consideration has entered into the problem, the 

 rotation for highest rate of volume production would be 220 years 

 rather than 180. There seems to be some mistake or oversight if 

 all the data have been correctly presented. 



On the basis of a rotation of 180 years it is shown that yellow 

 pine can be cut to 30 inches and sugar pine to 33 inches, yet the 

 cutting of both to 30 inches is recommended. Later on (page 32) 

 it is said that knotty trees under 32 inches in diameter can only be 

 marketed at a loss, so that it seems that a limit of 30 inches should be 

 advised for yellow pine only and 33 inches kept for sugar pine. The 

 condition of the tree, however, as determined by the condition of the 

 crown, is the prime factor in guiding the cuttings. Maturity is indi- 

 cated by flattened tops. From 12,000 to 18,000 feet per acre must 

 be removed in order to make the operation profitable, and it is esti- 

 mated that on this basis a second cut can be made in from 50 to (iO 

 years. 



The sugar pine stands are divided into two classes as a basis for 

 cutting, one in which the forest is made up of mixed but approxi- 

 mately even-aged groups, and the other in which -trees of all ages 

 are intermingled singly. For the former class of stands a group 

 selection, taking out from ()5 to 75 per cent of the stand by volume, 

 is advised. For the latter a system called single-tree selection, re- 

 moving from 75 to 85 per cent of the stand (better termed a clear 

 cutting, with scattered seed trees), is advised. With cuttings as 

 heavy as these, reproduction of sugar pine is not expected imme- 

 diately, except in the partial shade of the trees left, but after yellow 

 pine, fir, and cedar have come in, it is expected that the sugar pine 

 will get a start and ultimately occupy a dominant position in the 

 stand because of its more rapid and sustained growth. There is 

 some doubt if this result will take place, however. 



Planting of cut-over lands to facilitate sugar pine reproduction 

 is shown to be impracticable at present because of the poor germina- 



