NATURAL AREAS AND REGIONS 



153 



forms the western rim of the Rocky 

 Mountain Trench: 



Northern Belt. This is subject 

 to greater extremes, but less data are 

 available. Liard varies from 40 to 

 50 below zero during extreme winter 

 weather to 90 and above, during the 

 summer. These periods, however, are 

 of short duration, and generally it may 

 be stated that this region is in the same 

 isotherm as Quebec or Central European 

 Russia during January and that of 

 Edinburgh or Christiana, Norway, dur- 

 ing summer. The precipitation is from 

 16 to 20 in., nearly half of which falls 

 during the growing season. 



II. ORIGINAL BIOTA 



A. NORTHWESTERN MOIST CONIFEROUS 

 FOREST (COAST FORESTS) 



1. General 



The coast forests are characterized by 

 the giant size of the trees. These tower 

 200 to 300 ft. high and often reach 25 to 

 30 ft. in girth. The underbrush consists 

 chiefly of salal (Gaultheria shallon), in 

 drier situations, especially in Douglas 

 fir (Pseudotsuga taxifolia), with devil- 

 club (Echinopanaxhorridum), and salmon 

 berry (Rubus spectabilis} in the lower 

 and wetter situations. P. Z. C. 



Here the humid atmosphere favors a 

 luxuriant growth of ferns including 

 sword fern (Polystichum munitwri), 

 maiden hair fern (Adiantum pedatum), 

 oak fern (Phegopteris dryopteris), the 

 latter often carpeting large areas of the 

 forest floor; while the western polypody 

 (Polypodium vulgare, var. occidentale) , 

 clothes the large trunks and branches 

 of the soft maples (Acer macrophyllum) . 

 The combined effect of these ferns, to- 



gether with an abundance of mosses and 

 lichens hanging in festoons from the 

 branches, is to impart to the coast forest 

 a close resemblance to a tropical jungle. 



Near the margin of such an environ- 

 ment the cascara tree (Rhamnus pur- 

 shiana), is found at its best. The bark 

 of this tree is the Cascara Sagrada of 

 commerce, and in recent years British 

 Columbia has been called on to furnish a 

 very large proportion of the world's 

 needs of this valuable medicine. /. D. 



Mammals and birds 2 E. A. P. The 

 mammals include the coast long-tailed 

 shrew (Sorex obscurus longicauda] ; 

 Rhoads deer-mouse (Peromyscus manicu- 

 latus macrophinus) northerly; Bangs 

 deer-mouse (P. m. oreas) southerly; 

 Wrangell lernming-vole (Synaptomys 

 borealis wrangeli) northerly; Wrangell 

 red-backed vole (Evotomys wrangeli} 

 northerly; coast red-backed vole (Evot- 

 omys caurinus] southerly; long-tailed 

 vole (Microtus mordax macrurus), Sitka 

 deer (Odocoileus columbianus sitkensis) ; 

 elk (Cervus canadensis roosevelti] south- 

 erly; black bear (Ursus americanus). 

 The so-called white bear (Ursus ker- 

 modei} from Gribble Island, is probably 

 only an instance of albinism. Several 

 forms of brown and grizzly bears (Ursus 

 chelidonias, U. atnarko, U. quakiutl, U. 

 warburtoni, and U. pervagor) are de- 

 scribed from the coast forests, but their 

 ranges are not well defined. The 

 northwest wolf (Canis occidentalis gigas}, 

 preys on the deer. The northwest coast 

 skunk (Mephitis o. spissigrada] , and the 

 Pacific raccoon (Procyon psora pacified}, 

 and the British Columbia Seweelek 

 (Apoldontia v. columbiana) , extend only 

 a short distance northward along the 

 coast; while the British Columbia mink 

 (Mustela v. energumenos} , and the north- 

 west marten (Martes a. caurina} range 

 farther north and into the interior. 



B'f ds more or less characteristic of the 

 crast forests include the following: 

 Sika grouse, red-breasted sapsucker, 

 Oregon junco, lutescent warbler, Stellers 

 jay, Townsend's warbler, piliolated 

 warbler, chestnut-backed chickadee, 

 russet-backed thrush, varied thrush. 



* See page 181 (Oregon) for note on Mollusc*. 



