Recovery Plan for the Northern Spotted Owl - DRAFT

continued-Common Name Causal Agent Tree SpeciesCommon NameRed belt fungusCausal AgentFomes pinicolaAll dead conifersPouch fungusMISTLETOESDouglas-fir dwarfmistletoeCryptoporus volvatusArceuthobium douglasiiDead conifers, esp.ponderosa and lodgepolepinesDouglas-firWestern dwarfmistletoeLodgepole pine dwarfmistletoeA. campylopodum Ponderosa pineA. americanum Lodgepole pineLarch dwarf mistletoe A. laricis Western larchOak mistletoe Phoradendron sp. OaksIncense-cedar mistletoeRUSTSPhoradendron juniperinumssp. libocedriIncense cedarWestern gall rust Endocronartium harknessii Shore pine, lodgepolepineComandra blister rustWhite pine blister rustCronartium comandraeCronartium fibicola(introduced)Ponderosa pine,lodgepole pineWestern white pineSource: Bega( 1979), Boyce (1961), Hadfield et al. (1986), Hagel et al. (1987), Hepting (1971), Holsten et al. (1985), Partridge et al. (undated), Pettinger(1982), Sinclair et al (1987), and USDA Forest Service (1983)... I.... I I 1 1 " I' l l442organisms; i.e., those likely to strongly influence the structure of forests, arelisted in Table F.5. Most of the diseases in the region are native. White pineblister rust, however, is introduced and has had a major impact on populationsof five-needled pines.The type of disease typically changes as forest succession proceeds (Table F.6).Root rots tend to be more important in the early stages of succession whileheart rots and other decays and dwarf mistletoes tend to be more important inlater stages of succession, especially in old-growth forests. Root rots, however,can be an important disturbance in old-growth forests; e.g., PheUinus weilit in150- to 250-year-old mountain hemlock stands in central Oregon (Waring et al.1987). Franklin et al. (1987) implicate diseases as a major cause of tree mortalityin old-growth forests, especially in the West Cascades subregion. Theyare probably a more important cause of mortality than insects in this subregion.