Browsing can easily devastate Douglas-fir. Good practitioners totally eradicate a site of problematic pests (e.g., goats, hares, rabbits and possums) before a single tree is planted. One hare can destroy hundreds of seedlings in a night, and at leastone large South Island forest grower shoots them from a helicopter. Browsing mammals (hares, rabbits, goats, deer, etc) can make it impossible to grow Douglas-fir unless they are controlled. Possums continue to debark and debud trees until they are at least 10 years old. To establish Douglas-fir, much better animal control is required than would be the case for radiata pine. If, for one reason or another, pests are uncontrollable the location should be reconsidered. Insects are not usually a major problem, but there have been recorded epidemics of looper caterpillars7 and seed-eating chalcids8. Douglas-fir wood is not susceptible to common borer beetle.
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