THUJA PLICATA, Don. 

 Giant Arborvitae. Western Red Cedar. 



Size. Largest of the cedars; averages 100 to 150 ft. by 3 ft.; 

 maximum 200 ft. by 15 ft. 



Growth. Slow but persistent. Studies of 170 measurements on 

 Vancouver Island, and 46 measurements near Lake Slocan in B.C., 

 showed growths of 10 inches in 70 and 85 years; 20 inches in 115 and 170 

 years; and 30 inches in 180 and 235 years respectively. Life, 800 years. 



Root System. Heart. 



Bole. Very rapidly tapering and swell butted. 



Crown. Long, irregular, open, conical, frequently two leaders. 

 Usually very branchy and does not clean well. Crown often covers two- 

 thirds of the stem. 



Tolerance. Very tolerant; ranks with western hemlock. 

 Wood. Soft, brittle, not strong, very durable; 23 pounds. 



Reproduction. Prolific seeder with heavy seed years at irregular 

 intervals. Cones mature at the end of August and shed seeds soon. 

 Seed about 18 to a cone; small with small double wings; germination 

 percent high but vitality transient; often germinate in the fall. Moist 

 organic and mineral seed beds suitable; can grow in heavy duff. 



Range. Pacific coast, northern California to Sitka, Alaska, and 

 east to the west slope of the Rockies. Optimum, moist coast of southern 

 British Columbia. 



Climate. In general favorable; temperature down to -30 Fahr.; 

 precipitation varies from 20 to 100 inches. 



Soil. Chiefly moist situations; thrives on a wide range of soils if 

 sufficient moisture is present. 



Association. Occurs singly and in small groups with western 

 hemlock, Sitka spruce, lowland and Douglas firs; with redwood and hem- 

 lock in California. At higher elevations with pine, larch, and Engel- 

 mann spruce. 



General. Commercial importance is great because of large supply, 

 ease of working, and durability of wood. It is the chief shingle tree in 

 Canada, forming over half of the cedars' total which is 91% of all shingle 

 material. It also forms over J of the total cedar lumber cut which ranked 

 fifth in Canada in 1912. In the United States this tree, with the incense 

 cedar, is estimated to have 100 billion feet or 4% of the total stumpage. 

 In 1907 it supplied 7 billion shingles or over 3/5 of the total. 



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