SOME DISEASES OF NEW EXGLAXD CONIFERS. 



INTRODUCTION. 



NECESSITY FOR STUDYING THE DISEASES OF FOREST TREES. 



Very little attention has been paid to the study of diseases of forest 

 trees in the United States up to this time, and the reasons are obvious 

 enough. Up to within a few years the suppty of standing timber of 

 all kinds has been so large that a few diseased trees, more or less, scat- 

 tered over wide areas were of little account. The lumberman cut down 

 the sound trees and paid no attention to such as he recognized to be 

 of inferior value. The situation has changed within the last decades, 

 and a wide -felt demand has arisen among all classes of people for a 

 more economical and rational treatment of the existing forest lands, 

 and for reestablishing forests on denuded areas. In the primeval 

 forest the trees diseased because of fungous or insect attack were 

 ignored. They were few in comparison with sound trees, and the 

 price of a single tree was very low. At the present time, with a marked 

 appreciation in the value of timber, the agencies which injure trees for 

 timl)er are of more immediate interest to the owners of woodlands. 

 At this time the extent to which insects and fungi destroy trees can only 

 be guessed at. Their work of destruction goes on silently here and 

 there in the forest, and does not attract the attention of the casual 

 observer as do careless lumbering or forest fires. If the dead and 

 dying trees in a forest could be collected, they would represent a con- 

 siderable percentage of the total forest. Forest fires are alread}^ not 

 so common as the}^ used to be, and the lumberman of to-day is beginning 

 to understand that more can be realized from a given forest tract by 

 rational treatment than b}' indiscriminate cutting. Insects and fungi, 

 and other harmful agencies of less importance, are being studied with 

 the aim of arriving at a more complete understanding of their manner 

 of working. 



From its first growth until it falls a tree is subject to attacks of a 

 large number of insects and fungi, often resulting in stunted growth 

 or death. In many cases the injury is to the wood alone; the diseased 

 tree may remain standing for many years, and may be useful as a shade 



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