DISTRIBUTION AND OCCURRENCE
SPECIES: Tsuga heterophylla | Western Hemlock 



GENERAL DISTRIBUTION : 
Western hemlock occurs in the Coast Ranges from Sonoma County California
to the Kenai Peninsula in Alaska.  Inland it occurs along the western
and upper eastern slopes of the Cascade Range in Oregon and Washington
and west of the Continental Divide in the northern Rocky Mountains of
Montana and Idaho, north to Prince George, British Columbia
[10,56,57,78].


ECOSYSTEMS : 
   FRES20  Douglas-fir
   FRES21  Ponderosa pine
   FRES22  Western white pine
   FRES23  Fir - spruce
   FRES24  Hemlock - Sitka spruce
   FRES25  Larch
   FRES26  Lodgepole pine
   FRES27  Redwood
   FRES28  Western hardwoods


STATES : 
     AK  CA  ID  MT  OR  WA  AB  BC


ADMINISTRATIVE UNITS : 
     CRLA  GLBA  GLAC  LAVO  MORA  NOCA
     OLYM  REDW  SAJH  SEQU  WRST


BLM PHYSIOGRAPHIC REGIONS : 
    1  Northern Pacific Border
    2  Cascade Mountains
    4  Sierra Mountains
    5  Columbia Plateau
    8  Northern Rocky Mountains


KUCHLER PLANT ASSOCIATIONS : 
   K001  Spruce - cedar - hemlock forest
   K002  Cedar - hemlock - Douglas-fir forest
   K003  Silver fir - Douglas-fir forest
   K004  Fir - hemlock forest
   K005  Mixed conifer forest
   K006  Redwood forest
   K008  Lodgepole pine - subalpine forest
   K012  Douglas-fir forest
   K013  Cedar - hemlock - pine forest
   K014  Grand fir - Douglas-fir forest
   K015  Western spruce - fir forest


SAF COVER TYPES : 
   202  White spruce - paper birch
   205  Mountain hemlock
   206  Engelmann spruce - subalpine fir
   210  Interior Douglas-fir
   212  Western larch
   213  Grand fir
   215  Western white pine
   218  Lodgepole pine
   221  Red alder
   222  Black cottonwood - willow
   223  Sitka spruce
   224  Western hemlock
   225  Western hemlock - Sitka spruce
   226  Coastal true fir - hemlock
   227  Western redcedar - western hemlock
   228  Western redcedar
   229  Pacific Douglas-fir
   230  Douglas-fir - western hemlock
   231  Port-Orford-cedar
   232  Redwood


SRM (RANGELAND) COVER TYPES : 
NO-ENTRY


HABITAT TYPES AND PLANT COMMUNITIES : 
Western hemlock commonly occurs as a dominant or codominant on low- to
mid-elevation moist sites.  In northern Idaho, plant communities
dominated by western hemlock occupy the moist, moderate temperature
sites within the maritime-influenced climatic zone of the northern Rocky
Mountains.  Here, western hemlock can be found as the climax dominant
from 2,500 to 5,500 feet (760-1,680 m) and can dominate sites of all
exposures and landforms except wet bottomlands where it is replaced or
codominant with western redcedar (Thuja plicata) [19].  In the Gifford
Pinchot National Forest of Washington, the western-hemlock-dominated
zone includes the lower elevation moist forests of the western Cascades
[68].  In Mount Rainier National Park, Washington, the western
hemlock/devil's club (Oplopanax horridus) community occupies wet
benches, terraces, and lower slopes at low elevations [32].  The western
hemlock riparian dominance type in Montana described by Hansen and
others [39] is an infrequent cover type restricted to northwestern
Montana on toe-slope seepages, moist benches, and wet bottoms adjacent
to streams.  Published classifications identifying western hemlock as a
dominant or codominant are as follows:

Classification and management of riparian and wetland sites in northwest
  Montana [14].
Classification of montane forest community types in the Cedar River
  drainage of western Washington, U.S.A. [54].
The forest communities of Mount Rainier National Park [32].
Forest habitat types of Montana [59].
Forest habitat types of northern Idaho: A second approximation [19].
Forest types of the North Cascades National Park Service complex [5].
Forest vegetation of eastern Washington and northern Idaho [21]. 
A guide to the interior cedar-hemlock zone, northwestern transitional
  subzone (ICHg), in the Prince Rupert Forest Region, British
  Columbia [36].
Natural vegetation of Oregon and Washington [31].
Plant association and management guide [41].
Plant association and management guide for the western hemlock zone.
  Gifford Pinchot National Forest [68].
Plant association and management guide for the western hemlock zone: Mt.
  Hood National Forest [37].
Plant association and management guide. Willamette National Forest [42].
A preliminary classification of forest communities in the central
  portion of the western Cascades in Oregon [25].
Preliminary forest plant association management guide. Ketchikan area,
  Tongass National Forest [23].
Preliminary forest plant associations of the Stikine area Tongass
  National Forest [70].
Preliminary plant associations of the Siskiyou Mountain province [12].
Preliminary plant associations of the southern Oregon Cascade Mountain
  Province [11].
Reference material Daubenmire habitat types [69].
Riparian dominance types of Montana [39].
A study of the vegetation of southeastern Washington and adjacent Idaho
   [73].
Vegetation mapping and community description of a small western cascade
   watershed [40].
Vegetation of the Abbott Creek Research Natural Area, Oregon [53].

Related categories for Species: Tsuga heterophylla | Western Hemlock