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AnnoEus root disease 



Some Annosus root diseases are already causing damage on dry areas in western 

 North America. If an exotic strain were to be introduced, it would have "a high 

 potential to infest extensive areas of true fir and dry pine forests. Mortality in infested 

 areas would probably be high.* Other trees would suffer addidonal stress, becomin; 

 more vulnerable to odier introductions or stresses (USDA Forest Service 1991b). 



Spruce bark beetle 



During epidemics, the spruce bark beede {Tps typographus) spreads from dead or fallen 

 spruce to standing spruce and somedmcs pines and larches. The beetles carry vari- 

 ous fungi, some of which are extremely pathogenic. The risk of introduction would 

 be high in areas with spruce lumber or naturally dead spruce near coastal ports. 

 Once introduced, the beeUes could disperse by flight, eventually throughout the 

 Pacific Northwest (including Alaska) and east along the boreal spruce forests to the 

 AUantic. If the bceUe were accompanied by a more virulent fungus, such as Ophio- 

 stoma polomca, and nauve beedes also spread the fungus, "it could ... be as disastrous 

 to North American spruce as the Dutch elm disease was to elms." (USDA Forest 

 Service 1991b). 



In analyzing the threat posed by the polendal introducdon of Asian and Siberian tree 

 "pest" organisms, the authors of the Siberian assessment stated, 



...It is impossible to state the probability of extensive infestadon.... However, 

 since the risk of spread of these pests is high, large-scale infestauons and tree 

 mortality are likely to occur.... Loss of a significant proporuon of living trees 

 within stands would trigger complex changes in food supply and habitaL... 

 Detrital food chains — fueled by dead organic matter — ^would be favored, 

 while food chains that depend on living trees would collapse unless the sys- 

 tem recovered very quickly.... (USDA Forest Service 1991b). 



The Risk Assessment authors predict that mycorihizal fungi, several species of voles, 

 flying squirrels, and spotted owls could not make the U'ansition to a detrital food 

 chain. Deer and elk would be further limited by the increased scarcity of closed- 

 canopy forests, which provide winter forage and shelter Western yew, accipitcr hawks, 

 and salmonid fish would also decline (USDA Forest Service 1991b). 



New Zealand Importations 



In contrast to the size of the Siberian Risk Assessment Team, a risk assessment team 

 for logs imported from New Zealand consisted of only five scientists, assisted by 1 1 

 experts from New Zealand. In a fashion similar to the Siberian assessment, this report 

 gave deuiled attention to only a few of the potential introducuons: two diseases and 

 five insect species. The toul economic losses associated with introducdon of the 

 seven pesu evaluated are esumated to fall between $52 and J364 million, exclusive of 

 the costs of suppression, job loss, watershed damage, recreadon, or ecological dam- 

 age (USDA Forest Service 1992). 



Latlin (personal communicadon) has severely criridzed the assessment as being too shal- 

 low and hurried. He notes that die report ignored several European pests now estab- 

 lished in New Zealand. The assessment team originally failed to consult die major source 

 on insects found on Monterey pine {Pinus Todiata). Although this publicadon is in- 

 cluded in the list of references, inspection of the report's text shows that the relevant 

 informadon was not incorporated. Below are short sununaries of the potential dam- 

 age that two introduced pests from New Zealand could perpetrate on western forests. 



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