INTRODUCTION 



During the 1940' s, managers of ponderosa pine forest properties in the northern 

 Rocky Mountain States displayed increasing interest in the possibility of using sanita- 

 tion-salvage cuttings to prevent destructive outbreaks of the western pine beetle, 

 BendroQtanus bTevioomis LeConte (Coleoptera: Scolytidae) . Their interest possibly 

 stemmed from reports of tests and several operational applications of such cuttings made 

 during the late 1930 's in ponderosa pine forests in northeastern California and eastern 

 Oregon wherein the cuttings were credited with reducing intolerable tree mortality from 

 the pine beetle. During the mid-1930' s, in this northwest fringe of the North American 

 Great Basin, the concept of preventive control of the western pine beetle had become a 

 reality as a result of the development of the sanitation-salvage cutting method 

 (Bongberg; -"^ Johnson;^ Keen and Salman 1942; Orr 1942; Salman and Bongberg 1942). 



Forest entomologists coined the term "sanitation-salvage cutting" to refer to a 

 light silvicultural selection cutting designed to remove from overstory stands for 

 utilization certain merchantable ponderosa pine trees judged to be potential breeding 

 habitats for the western pine beetle. These trees are ordinarily of low vigor and 

 readily identified as the Risk 3 or Risk 4 trees of the four-rating Ponderosa Pine Risk 

 Rating System (see fig. 1) evolved by Salman and Bongberg (1942). Under this rating 



■"•J. W. Bongberg. Effectiveness of sanitation-salvage logging in reducing insect- 

 caused loss. Blacks Mountain Experimental Forest, season of 1940. USDA Bur. Entomol. 

 and Plant Quar. , Forest Insect Lab., Berkeley, Calif. Unpub. Rep. May 12, 1941. 



^Philip C. Johnson. Effect of sanitation-salvage cutting upon subsequent insect- 

 caused pine mortality. Blacks Mountain Experimental Forest, progress report, 1937-1943. 

 USDA Bur. Entomol. and Plant Quar., Forest Insect Lab., Berkeley, Calif. Unpub. Rep. 

 May 31, 1946. 



