PATHOLOGICAL MARKING RULES FOR IDAHO AND 



MONTANA 



By James R. Weir, Forest Pathologist, and Ernest E. Hubert, 

 Scientific Assistant 



INTRODUCTION 



From the standpoint of forest sanitation the marking of trees in the 

 administration of timber sales is fundamental. No other stage in the 

 timber-sale operation offers better opportunities for the practice of 

 such principles as will result in checking the spread of forest-tree dis- 

 eases. Everything consistent with existing economic conditions should 

 be done to reduce the chances of infection of the present timber crops 

 in every stage of their development and to insure, so far as possible, a 

 healthy reproduction. In order to do this, it is important that the 

 marking rules should be so formulated as to exclude all but thrifty and 

 healthy trees for the left-over stand and for seed trees. Attempts should 

 be made to apply specific disease-prevention rules for marking to the 

 various forest types of Idaho and Montana, so far as is consistent with 

 economic limitations and the systems of cutting. It is believed that 

 efforts should be made so far as practicable to have the Forest Service 

 take over entirely the execution of all forest sanitation work and leave 

 as little as possible in the hands of the purchaser. 



This paper attempts to formulate such rules for definite types and 

 systems of cutting common to the National Forests of Montana and 

 Idaho, so far as conformable to practical application. 



THE OBJECTS OF MARKING 



The principal objects of marking in Forest Service timber-sale opera- 

 tions are silvicultural in character. They are intended to secure a 

 maximum cut without overlooking the necessary steps toward a future 

 crop of maximum volume and quality. In order to fulfill the latter 

 object, it is highly important to reduce the amount of unmerchantable 

 material in the stand caused by fungi and other deteriorating agents 

 and to prevent loss of desirable reproduction. For these reasons all 

 marking regulations should contain specific instructions regarding the 

 cutting of all disease-infected trees, whether below the diameter limit 

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