A CRITICAL-ASSESSMENT OF RISK CLASSIFICATION SYSTEMS FOR THE MOUNTAIN PINE-BEETLE

Hazard/risk systems developed for mountain pine beetle management traditionally have attempted to describe the potential for timber loss in pine stands due to outbreak phase populations. A variety of stand and site characteristics, as well as climatic conditions, have been used. In this study, four hazard/risk systems were evaluated using data from 105 stands in northern Montana None of the systems evaluated were found to predict adequately mountain pine beetle induced mortality which occurred in the test stands. Possible reasons for the lack of predictive ability of these systems include: (1) confusion in terminology used in hazard/risk rating for mountain pine beetle; (2) lack of consideration of the mountain pine beetle population phase (e.g. endemic or epidemic) during rating system development; (3) the need to include more information concerning mountain pine beetle population dynamics; (4) the need for inclusion of the spatial nature of both beetle populations and stand conditions.