4 BULLETIN 658, U. S. DEPARTMENT OF AGRICULTURE. 



estimate at its face value may find upon cutting the stand that a great 

 deal more rot is encountered than was expected. This fact alone 

 could easily result in the logging operation turning out a loss instead 

 of a profit, especially if the logging chance is not a favorable one. 

 Such failures doubtless do not encourage the undertaking of further 

 contracts, and fewer timber sales are the result. This has its ultimate 

 effect upon the forest as a whole in an economic way. 



Recent studies made of the rots occurring 1 in forest trees have 

 given information concerning the amount of decay prevalent in dif- 

 ferent age classes and in different sites for a particular species of tree. 

 These studies have indicated that the decay in a tree or a stand 

 varies with such factors as age of stand, site, density, injuries, and 

 moisture relations. Such being the case, a disease survey of the sales 

 areas made either as a separate pathological survey or in conjunc- 



Fig. 3.- — Typical rot of Trametes pini (honeycomb rot) in white pine. 



tion with the usual timber surveys would prove of immense value in a 

 closer estimate of the sound board-feet contents of the stands. A 

 disease survey in conjunction with the timber-survey work would no 

 doubt be the more feasible plan of the two, since it would require 

 no additional men for the crews and should not appreciably affect 

 the cost per acre. All that would be required in order to secure the 

 disease data in more accurate form is the training of one of 

 the members of each unit crew in the proper methods by which the 

 various pathological determinations are made. This would mean the 

 ability to judge more accurately the cull percentage due to rot and 

 the ability to recognize all the outward indications of decay as well 

 as the principal fungi attacking forest trees. Preferably, the esti- 

 mator should be the one selected to assume this duty, as it is his indi- 

 vidual work which determines the total estimate and the cull percent- 

 age of the stand. 



^leinecke, E. P. 

 G2 p. 1916. 



Forest pathology in forest regulation. D. S. Dept. Agr. Bui. 27J 



