no FOREST COMMISSIONERS REPORT. 



These measurements were all taken in unmanaged stands 

 just as they occurred in the forest, and show what may be ex- 

 pected from natural birch stands. Where the stands are near 

 settlements and easily accessible, the yield can be increased by 

 thinnings, which not only utilize the smaller and less desirable 

 trees but also increase the growth of those that remain. 



Outlook for Future Supplies. 



Forest conditions and forest policies are now changing so 

 rapidly that it is difficult to predict what conditions will prevail 

 many years in the future. In the case of paper birch, however, 

 it seems fairly certain that for a good many years the supply 

 will not be exhausted. There are extensive areas of mature 

 birch which should be cut as soon as possible, and there are also 

 considerable stands of young material of various ages which 

 will later be available. Future supplies will be brought from 

 greater and greater distances and from places now inaccessible, 

 as better transportation facilities and an increase in the value 

 of birch eventually bring them to market. These future sup- 

 plies will imdoubtedly come largely from Maine and New 

 Hampshire. The Lake States, particularly Minnesota, may in 

 time furnish a small supply, but the bulk of the material will 

 still come from the Northeast. 



Whether the supply of paper birch will last indefinitely is a 

 much more difficult question. As already stated, paper birch 

 represents a distinctly transitory forest type, and the present 

 stands are bound to be replaced, in time, by the types natural 

 to the locality. Fires and clearings give birch a chance to re- 

 occupy old areas and seize upon new ones, but with the pre- 

 vention of forest fires and the more permanent occupancy of 

 agricultural lands these factors will be less influential in the 

 future. Extensive stands of paper birch may, therefore, tend 

 to become scarcer and scarcer, but it is very doubtful whether 

 they will ever disappear altogether. Clearings of one sort or 

 another will enable it to get a footing, and the passing of the 

 paper birch is too remote a contingency to be accurately fore- 

 told. 



