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The increased controversy over cutting America's remaining old-growth forests has af- 

 fected North American timber supplies in western forests and generated interest in 

 importing logs from foreign countries. The dissolution of the Soviet Union and asso- 

 ciated trade restrictions have opened the forests of Siberia to utilization by western 

 nations. Other countries, such as New Zealand and Chile, also have raw materials 

 available for the North American market In relation to this paper, the most importar 

 question raised by imporution of logs are the possibilities of introducing new exotic 

 pests into North America and reintroduction of existing exotic pests at new locations. 



Siberian Importations 



In response to pressure by scientists and politicians, APHIS requested the Forest 

 Service to conduct an assessment of the risk of importing pests on logs from Siberia 

 in 1991. The assessment team consisted of 43 forest scientists from federal and sute agen- 

 cies and universities. The team concluded that "the close similarity between [Siberia 

 and similar latitudes of North America] promises to produce many taxa from Siberia 

 that will find suitable hosts in various parts of the forests of Western North America.... 

 Some species are likely to become serious pests" (USDA Forest Service 1991b). 

 Siberian larch (Lanx siberica) was assumed by the team as the primary species to be im- 

 ported. The assessment team determined that 175 species of arthropods, nematodes, 

 and fungi were associated with Siberian larch. They identified and reviewed 36 "rep- 

 resentative" species from each of three groups that could be imported on logs with 

 attached bark: pests residing on the outer bark, found inside the bark, or within the 

 wood (USDA Forest Service 1991b). 



An economic analysis predicting revenue losses was conducted, based on the assump- 

 tion of infestation by the above 36 representative species. The analysis estimated the 

 net present value of potential losses at between $24.9 million (best-case scenario) and 

 $58 billion (worst-case scenario). These figures represented only the potential im- 

 pacts to commercial timber species in the western U.S.; they did not consider ecosys 

 tem damage, impacts to nonconsumptive industries associated with forested land, or 

 harm to agriculture. 



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