MANAGEMENT OF WHITE PINE 365 



interval. On rich, moist sites it is occasionally necessary to weed the 

 crop a third time, in order that the best advantage may be taken of 

 the very productive land. When this work is begun at the proper 

 lime, that is, before the crop has passed the small sapling stage, it 

 can be done at the rate of ly^ to 2^ acres per man per day. On the 

 Harvard Forest areas which have been weeded twice and which are in 

 condition to produce valuable timber without further expense have 

 cost, for reproduction, from $7 to $9 per acre. 



EXPECTABLE YIEEDS 



Exact figures bearing on the final yield of such weeded stands of 

 mixed hardwoods and pine are lacking. They can be approximated, 

 however, by reference to existing stands where, over small areas, similar 

 mixtures of species have reached maturity. The yield for well-stocked 

 natural-pine stands, as based on the mill figures, runs from 40,000 to 

 55,000 feet per acre at 6 years. For mixed stands of the same age 

 the yield varies from 20,000 to 35,000 feet per acre being higher 

 according as the percentage of pine in the mixture is higher. These 

 figures all apply to natural stands in which irregularity of stocking 

 and abnormalities of crown development create a very considerable 

 waste of growing space. It seems fair to assume, therefore, that in a 

 stand where both distribution and mixture^ have been properly regu- 

 lated by early weedings, the yield will not only be better in quality, 

 'nit at least equal in quantity the production of volunteer growth. 

 On suitable sites red oak and white ash, for example, will produce 

 two to three log timber of the highest quality at 60 years. Specula- 

 tion as to lumber prices 60 years hence is perhaps uncertain, but it 

 ^ certain that they will be no lower than they are today. If, there- 

 fore, the mixed stands produced by the management above described 

 are reckoned as yielding a final valume of 35,000 feet per acre, the 

 value of the crop at present stumpage prices will be from $400 to $500. 

 Given a reasonable security from fire and fairly equitable taxation this 

 seems a satisfactory return on an investment of not less than $10 

 per acre. 



SIMPLEST POLICY FOR THE REGION 



It is difficult to reduce practical silviculture to a rule-of-thumb. 

 Only the knowledge that comes from residence experience in a given 



