274 A NATIONAL PLAN FOR AMERICAN FORESTRY 



A shortage of timber for production of gum would be offset by 

 increased production of wood naval stores, but a return to gum naval 

 stores could be expected with recovery of timber resources. 



Gallons of turpentine and barrels of rosin do not express so directly 

 the equivalent timber requirement as do feet of lumber or cords of 

 pulpwood. Timber requirements for naval stores can be expressed 

 in acres better than in board feet or cords. The acreage would depend 

 upon factors of size or trees and number of trees per acre, which 

 vary from time to time and one locality to another. Based on typical 

 stands at the present time, it would require more than 18 million 

 acres of turpentine orchards to produce annually the 1929 volume of 

 naval stores. This estimate is based upon an average production 

 of 30 units of naval stores to the crop 1 and an average of 10 active 

 cups per acre. Improved turpentining practice and forest manage- 

 ment would reduce this figure by increasing the yield per crop and 

 increasing the trees per acre. 



Gum naval stores production cannot be maintained without the 

 timber, but timber required does not constitute the forest drain in 

 this case. A tree after being turpentined is available for lumber or 

 other wood products. The loss in volume of wood usable as lumber 

 is represented by the butt of the turpentined tree and is estimated 

 at a half billion board feet measure for naval-stores production as 

 of 1929. 



MINOR WOOD PRODUCTS 



Variations in the minor wood products shown in table 13, with 

 the exception of shingles and veneer logs, have held within a rather 

 narrow range over the past 30 years. These products not only 

 occupy a relatively small place in total requirements, but with the 

 exceptions noted, give no evidence of consumption trends of special 

 significance. 



Shingle production, which dropped 50 percent from 1910 to 1920, 

 showed resistance to further loss thereafter. It is possible that the 

 large volume of residential construction from 1923 to 1928 had some- 

 thing to do with this stability and that for a normal volume of con- 

 struction a further decline in shingle production might be expected. 



Consumption of veneer logs increased rapidly prior to 1910. There 

 was no great change from 1910 to 1920, but consumption practically 

 doubled from 1919 to 1929. This is due undoubtedly to a growing 

 appreciation of the advantages of plywood and the extension of its 

 use into new fields of construction. The prospects are for further 

 increase in the consumption of veneer material, and because this 

 represents an increasing demand for high-grade logs, it has consider- 

 able significance in relation to future timber requirements. The ratio 

 of veneer logs to saw timber was roughly 1 to 100 in 1910 and 1 to 

 30 in 1929. 



Table 13 shows little change in quantity of distillation wood 

 consumed. There has been, however, a decline in hardwood con- 

 sumption balanced by an increase in softwood. The latter is account- 

 ed for by increased production of wood turpentine and rosin, which 

 is discussed under naval-stores requirements. Decline in consump- 

 tion of hardwoods for distillation has been due to the manufacture 



1 A crop is 10,000 cups. A unit consists of 1 cask (50 gallons) of spirits turpentine and 3H barrels of rosin. 



