712 A NATIONAL PLAN FOR AMERICAN FORESTRY 



on the better sites; we therefore have not extended our idle land or 

 had any serious watershed problems as a result of this unprecedented 

 epidemic, but much of the land on which the chestnut formerly pre- 

 dominated is permanently reduced in commercial value as a result 

 of the change to less profitable species. This loss of productiveness 

 of the former chestnut land is an even more serious matter than the 

 immediate loss of the merchantable chestnut stands. 



Where the disease has run its course and killed practically all the 

 trees, the causal fungus has decreased in abundance locally for lack 

 of food material, in some places to an extent sufficient to permit the 

 new sprouts to attain a considerable size and even to bear nuts 

 before becoming infected. In the cases that have been kept under 

 observation for a sufficient length of time the evidence is that these 

 new trees are susceptible. Despite much search by both govern- 

 mental and private agencies, no native trees that have been tested 

 so far have shown enough resistance to enable them to produce mer- 

 chantable stands in the presence of the disease. During the past 

 20 years large numbers of promising trees and sprouts which con- 

 tinued for a while to develop in the presence of the blight have finally 

 succumbed. Trees and sprouts in 200 different localities in 18 States 

 are still under observation by the owners in cooperation with the 

 Department to determine if they really are resistant. While it is to 

 be hoped that some individual native trees may yet be found so 

 nearly immune that they can be used as propagating stock for the 

 replanting of the American chestnut, the statements recently given 

 prominence in the public press that the chestnut is coming back, are, 

 to say the least, premature. Strenuous efforts are being made to 

 find Asiatic chestnuts that will be resistant both to blight and to 

 American parasites, or to produce hybrids with the American chest- 

 nut that will serve the same purpose. These efforts may ultimately 

 give us as good a tree as the one we have lost; but any such result 

 must require many years of work, and if actual reestablishment of 

 all the chestnut forests prove practicable, it will require generations 

 to accomplish it. 



The white pine blister rust, perhaps as well known as the chestnut 

 blight, stands in quite a different category from the chestnut disease. 

 It was introduced to this country from Europe, though it may have 

 come originally to that continent from Asia. In the eastern United 

 States it works more slowly than the chestnut blight, but is neverthe- 

 less an unusually conspicuous disease and was recognized at a rela- 

 tively early stage in its American development. One weak point 

 in its life history, namely, its need for a currant or gooseberry bush 

 as an alternate host, has made it possible to evolve a method of pro- 

 tecting our most valuable northern white pine stands before it had 

 time to cause great injury. Reproduction has been considerably 

 reduced in some places in the Northeast and in the Lake States, but 

 the control campaign has in general safeguarded us against heavy 

 losses in merchantable stands and promises to make it possible to con- 

 tinue the growth of white pine in most of its original commercial 

 range. The only places in the main commercial range where the 

 northern white pine may be forced out as a commercial species are 

 some in which the cost of eradication of the currants and gooseberries 

 is excessively high or where attack by other diseases and insects makes 

 the species too difficult to maintain when the added costs of blister- 



