Recovery Plan for the Northern Spotted Owl - DRAFT

Table F.3. Major tree species in the region and their relative importance by subregion.Species West Cascades Klamath East CascadesSitka spruce M mWestern redcedar M MWestern hemlock M MSitka Western Mixed Mixed Douglas- GrandSpruce Hemlock Conifer Evergreen fir FirZone Zone Zone Zone Zone ZoneDouglas-fir m M M M M MPacific silver fir - mPacific madrone m m MTanoak - - MWhite/grand fir - - M m m MPonderosa pine - - M M M mLodgepole pine - - m - m MWestern larch - - - - - MiiM = major species m = minor speciesNote: Not all species in a type are listed Some that are listed above may be classed as absent (-)only (e.g., riparian) or are not widely distributed across the type.(adapted from Franklin and Dyrness 1973)because they are present in special environmentsI/Characteristics of Forest Types of the Three SubregionsThe general characteristics of the forest types of the Pacific Northwest are welldescribed in Franklin and Dyrness (1973). A skeletal description of the subregionsincluded in this report is made to provide a brief context for the sectionsof the report to follow. In the West Cascades subregion, northern spotted owlsare found in the Sitka Spruce Zone, the Western Hemlock Zone, and into thePacific Silver Fir Zone, the latter of which is not fully described here, althoughsome owls may live in these forests. The Sitka Spruce Zone is a narrow coastalstrip normally a few miles in width, except where it extends up river valleys.Its proximity to the ocean and summer fogs, and presence of Sitka spruce(Table F.3), differentiate this zone from the Western Hemlock Zone, which hasmany of the same species.The Western Hemlock Zone (Table F.3) occurs over much of the lowlands westof the Cascade Mountains, and is often dominated by Douglas-fir as the majorseral tree species; western hemlock is commonly found in all canopy layers inold-growth forest. Its upper boundary with the Pacific Silver Fir Zone oftencorresponds to the line of perennial snowpack in winter months. The portionof the Pacific Silver Fir Zone which contains owl habitat also has Douglas-fir asa seral species, but increasingly Pacific silver fir replaces western hemlock asthe late successional tree dominant. The wetter plant associations may receiveup to 160 inches of annual precipitation, and the driest plant associations may429