Swiss needle cast has become increasingly severe during the last decade 

 along the north Oregon coast. Diseased stands appear yellow and grow 

 poorly (left) connpared to healdiy stands (right). 



Trees with Swiss needle cast may lose all but the current year's needles 

 (left), in contrast to healthy branch (right). With so little foliage 

 remaining for photosynthesis, tree growth declines and some trees die. 



low, in contrast to adjacent natural stands that 

 are green and vigorous. Most plantations with 

 severe symptoms are 10 to 25 years old and 

 within 1 5 miles of the coast in the fog zone. 

 Much of this area was previously dominated 

 by hemlock, spruce, or western redcedar. Why 

 this native disease has become so severe in this 

 area remains unclear. 



The severity of symp- 

 toms differs considerably 

 among individuals in the 

 Douglas-fir population, 

 indicating that tolerance 

 exists within the species. 

 The current management 

 recommendation for 

 areas with moderate or 

 severe damage is to favor 

 species other than Dou- 

 glas-fir whenever pos- 

 sible. If Douglas-fir is 

 planted, seed should be 

 from parent trees that 

 performed well in the 

 coastal fog zone. 



Black bears injure 

 and kill young Doug- 

 las-fir — ^Black bears peel 

 and eat the inner bark of 

 young conifers, especially 

 Douglas-fir, in spring 

 when the inner bark is 

 succulent and sugar con- 

 tent high. When the en- 

 tire circumference of the 

 bole is peeled, the tree 

 dies. Partial peeling can 

 reduce tree growth and 

 vigor, and provide an 

 entry point for organisms 

 that decay the valuable 

 butt log. An Oregon De- 

 partment of Forestry 

 study of Coast Range 

 bear damage found that 

 for every tree with its 

 entire circumference 

 peeled, at least two other trees were partially 

 peeled. 



Bear damage is common in Douglas-fir 

 stands in the 16- to 25-year age class, often 

 soon after the stands have been thinned. In 

 these stands, bears prefer the most vigorous 

 and largest diameter trees. Although bears 

 damage trees throughout the Coast Range and 



Oregon — 28 



