sitka spruce: uses, growth, management. 11 



The species attains its maximum development in Washington and 

 Oregon. The average tree found in the virgin forest has a height of 

 about 230 feet and a diameter of 4 feet, measured 15 feet above 

 ground. North of the optimum range in British Columbia it grows 

 to maximum diameters of 8 to 12 feet and heights of 160 to 180 feet; 

 but ordinarily it is only 3 to 6 feet in diameter. 6 In Alaska, too, its 

 average diameter is 3 feet and its height about 150 feet, but single 

 trees frequently exceed this. In California it is smaller than farther 

 north and becomes only a medium-sized tree. This subject is dis- 

 cussed more fully under the heading " Growth." 



LONGEVITY. 



Sitka spruce is a long-lived tree. Sudworth reports a maximum age 

 of 750 years. 7 During the recent study, however, the oldest tree that 

 could be found was 586 years of age. It is doubtful whether many 

 individuals ever reach an age of over 600 years, and the mean mature 

 age is not more than 450 years. 



DISTINGUISHING CHARACTERISTICS. 



An outstanding characteristic of the appearance in the forest of 

 Sitka spruce is its bark (PI. VII). The thin, stiff, cupped, and 

 elliptical dark purple-gray scales 1 or 2 inches in diameter make 

 this species easily distinguishable from its associates in the stand. 

 Little protection is afforded to the living tissues, however, by the 

 bark, which is only one-half to 1 inch thick. 



The needles are also of distinctive appearance. In spring the yel- 

 lowish green color of new needles in sprays that bend downward 

 limply at the ends of the branches stands out in contrast with the 

 dark bluish green of the older needles ; and although the young leaves 

 are soft and velvety to the touch, during the remainder of their 5 to 

 6 year existence they are stiff and stand out straight in all directions 

 around the twig, each needle tip being keenly pointed and quite 1 

 bristly to the touch. The leaves are somewhat flattened, only indis- 

 tinctly four-angled, and about 1 inch long. 



The cones, too, exhibit peculiarities by which this species may be 

 identified. They have an average length of 3 inches, are light 

 brown in color, elliptical in shape, and hang down conspicuously 

 from < lie upper branches. The cone scales are thin and papery, 

 witli irregular margins but slightly pointed in general outline, and 

 are firmly attached to the central stalk of the cone. Maturity is 

 reached at the end of one year's development; soon thereafter the 

 scales open and release the small dark brown seeds with their large 

 thin wings adhering to them. Most of the cones drop from the 



•" Porartf of BrltlHh Colombia," \>y EL. s. wiilfford and B. D. Crai*. p. 199, 1918. 

 ' " Pored Treei of th<- Pacific Blope," Q. B. Sudworth, p. 83, 1008. 



