Recovery Plan for the Northern Spotted Owl - DRAFT

endemic to the Pacific Northwest). Many of the species native to this regionhave not been described or named, and the number of known species probablyrepresents less than half of the estimated species (J. Lattin, Oregon StateUniversity, pers. comm.).Twenty-three species of terrestrial arthropods, most of which are wingless andflightless, are considered to be old-growth associates (J. Lattin, Oregon StateUniversity, pers. comm.). Camel crickets of the genus Prtstoceuthophilus andTropidischia xanthostoma are found in old-growth forests in the hemlock andsilver-fir zones, and they occur on the forest floor under logs and debris. Somespecies in this group of older-forest associates belong to very small genera andare considered rare, including Boreostolis americanus, Metrius contractus,Promecognathus laevissimus, Zacotus mnathewsti and Lobosoma honidun. Allof these species belong to genera that have only one or two described speciesand are often relics of past geologic history. One unique predator-prey relationshipexists in this group between the prey species Harpaphe haydenianaand the predator Promecognathus laevisstnus. H. haydeniana is a distinctivelymarked millipede that is a very important shredder of litter and, therefore, aninitiator of nutrient cycling. The species is marked brightly and produceshydrocyanic gas when disturbed. The production of cyanide is a deterrent tomost predators except P. laevissimus, which is specialized for feeding on thismillipede by its tolerance of cyanide gas. P. laevissimus is a terrestrial groundbeetle found in mature forests on the west side of the Cascade Mountains.There are also 17 species of insects from 13 families (Table D.7) that areassociated with coarse woody debris in western coniferous forests (J. Lattin,Oregon State University, pers. comm.). The decomposition of coarse woodydebris is a slow process in a natural ecosystem, and in the Pacific Northwestmany hundreds of invertebrate species have evolved to utilize logs for food orhabitat (Schowalter et al. 1991, Parsons et al. 1991, Moldenke, unpublisheddata). Though many of these species may have similar ecologic roles, thenatural process is not understood enough to know whether some or many areredundant for system function. However, the diversity of species itself may bea useful management tool to detect changes in the effects that logs may beexerting on the old-growth system.Vascular PlantsOne hundred and forty-four species of vascular plants that occur within therange of the northern spotted owl are older-forest associates or are listed as"species of special concern" by one or more of the three states (Table D.8).Seventy-six of the species on the list are associated with older forest ecosystems(Ruggiero et al. 199 lb). These plants include several species that havegenerated significant interest including the Pacific yew and Port Orford cedar.The Pacific yew especially is of interest because of the chemical taxol, whichcan be extracted from yew bark and is being tested as an anti-cancer drug.Port Orford cedar occurs only in a restricted area of northwestern Californiaand southwestern Oregon and is susceptible to root disease. No opportunitieswere identified specifically to provide measures to benefit these species, butmanagement of habitat for owls is likely to provide them with habitat support.Fungi and LichensThe list of fungi and lichens contains eight species. These species were identifiedas older-forest associates by Ruggiero et al. (1991b), and of these, two arespecies of special concern in one or more of the three states. Lichens of the356