A NATIONAL PLAN FOR AMERICAN FORESTRY 31 



expenditures of sportsmen, and the value, chiefly of birds, as destroy- 

 ers of insects. The Biological Survey estimates the total positive 

 national value of wild life at over $1,000,000,000 annually. 



The commercial fisheries of the Mississippi and its tributaries in 

 1930 produced values of $4,385,000. For the year ending June 30, 

 1932, approximately 4,850,000 State licenses carried the angling 

 privilege. The value of fishing tackle sold annually was estimated in 

 1929 by a trade association at $25,000,000. 



THE DEPLETION OF WILD LIFE 



In general wild life has decreased and is still decreasing on much of 

 the forest land of the country. Some species have been almost exter- 

 minated. This is also true of fish. Many waters which were well 

 stocked only a few years ago are now seriously depleted. 



The reasons are the far greater number of hunters and fishermen, 

 the lack of adequate control, disease, and the deterioration or destruc- 

 tion by fire or otherwise of forest cover and other essential conditions 

 of habitat. The floods and erosion which commonly follow forest 

 destruction or deterioration are an important cause of the scarcity of 

 fish. 



THE POTENTIALITIES OF WILD LIFE UNDER MANAGEMENT 



The numbers of game animals on the national forests are estimated 

 to have increased 40 percent between 1926 and 1931 as a result of 

 management. Certain species, such as deer, are unquestionably in- 

 creasing appreciably over considerable areas in many parts of the 

 country and under favorable conditions, including the regulation of 

 hunting. 



In general the wild-life population of the forest is far below what it 

 might be. One of the important problems is to work out forms of 

 management on the principle of sustained yield, which involves proper 

 stocking, the furnishing of food and cover requirements, protection 

 from natural enemies and other injurious factors, and the removal of 

 surplus only. 



One of the most important aspects of management for land forms of 

 wild life is that of coordination with timber production and utiliza- 

 tion, and the grazing of domestic livestock. 



Special aspects of the problem of building up numbers of fish include 

 their introduction into waters in which they are not native, artificial 

 propagation and stocking, protection from overfishing, and the im- 

 provement of streams and lakes to provide more favorable conditions. 

 The beneficial effects of forestation on the latter phase can scarcely 

 be overestimated. 



One of the complications in wild-life management is that of separate 

 land ownership and wild-life control except where the land is owned 

 by the States. Land ownership may be either private, State, or 

 Federal while wild-life control rests in the State. This phase of the 

 problem involves both wild-life regulation and the possibilities of 

 returns to the private owner. Similar complications exist in the case 

 of fish. 



