906 



A NATIONAL PLAN FOR AMERICAN FORESTRY 



shelves and thus meet varying demands for different classes of ma- 

 terials. At one time saw timber may be in heavy demand ; at another, 

 pulpwood from thinning the groups of smaller trees. 



Since American examples of intensive forestry practice with ade- 

 quate record keeping over long periods of time are lacking, the desir- 

 able growing-stock conditions in a forest developed according to the 

 principles discussed above are best shown by citing a European ex- 

 ample. The communal forest of Couvet in the Canton of Neuchatel, 

 Switzerland, is appropriate owing to careful direction of its manage- 

 ment for many years by the eminent Swiss forester Dr. H. C. Biolley 

 and owing also to the careful, detailed records (5). This forest, under 

 continuous-yield management for many years, has been subjected 

 since 1890 to a careful procedure of building up the growing stock in 

 order to improve the volume and quality of production. To a 



VOLUME 

 CU.FT. 



GROWING STOCK 1890 



VOLUME 

 CU.FT. 



SMALL 

 TIMBER 



LARGE 

 TIMBER 



6 6 10 I Z 14 16 18 20 22 24- 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 SMALL MEDIUM LARGE 

 GROWING STOCK 1927 



3000 



.6 8 10 12 14- 16 18 20 22 24 26 28 30 32 34- 36 38 40 42 44 46 48 50 52 54- 56 58 60 SMALL MEDIUM LARGE 

 DIAMETER BREAST HIGH (.NCHES) TIMBER GROUP TOTALS 



FIGURE 3. Distribution of cubic volume by diameter classes on average acre, communal forest of Couvet, 



Switzerland. 



remarkable degree, this has been accomplished without any impair- 

 ment of the periodic cut at any time and with a material increase in the 

 later periods. 



Figure 3 shows graphically the condition of the stand in 1890 and 

 its condition in 1927. The figures have been converted as accurately 

 as possible from metrical units to English measurements and are in 

 terms of the average acre in one division of the forest. The volume 

 of the growing stock has been built up from about 1,246 cubic feet 

 per acre to about 4,840 cubic feet per acre. 



The annual cut per acre has been increased from 74 cubic feet to 

 128 cubic feet, and the average size of the trees cut more than doubled. 

 The latter point is of extreme importance in increasing financial 

 returns, owing to the higher unit value of large trees. The annual 

 net returns did in fact increase during this period from $8.41 to $25.03 

 per acre. In America the closest resemblance to this Swiss example 

 in species and growth conditions is to be found in the forests of the 

 north Pacific coast, but a study of these diagrams will be instructive 

 for forest managers in other regions as well. Some of our hardwood 

 types can not be expected to bear any clos^ resemblance to this 

 example. 



