Forests of Alaska 



369 



about 74 percent is western hemlock, 

 20 percent Sitka spruce, and 6 percent 

 western redcedar and Alaska-cedar. 

 The average stand on an acre of com- 

 mercial timber is approximately 20,000 

 board feet, but individual logging 

 units with 40,000 board feet or more 

 are not uncommon. 



The prevailing timber type of the 

 Tongass Forest consists of a mixture 

 of the species named previously. It is 

 designated as the western hemlock 

 type. Mature hemlock trees average 

 between 3 and 4 feet in diameter, are 

 usually quite clean-boled and well- 

 formed, and are sound until maturity 

 is reached. After maturity, dead tops 

 and butt rot develop rapidly. 



Sitka spruce, the other dominant 

 member of the western hemlock type, 

 is a larger tree than the hemlock, 

 reaching at maturity an average diam- 

 eter of 5 feet at breast height and a 

 maximum of 8 feet or more. It usually 

 occurs singly or as small clumps of 

 trees scattered throughout the hemlock 

 stands. More light-demanding, it keeps 

 its head above the neighboring hem- 

 locks and cedars. Its long, slightly 

 tapering, branch-free bole and its 

 great size make Sitka spruce an impres- 

 sive feature of the Alaska forests. 



The western redcedar and Alaska- 

 cedar usually occur in clumps in the 

 mixed forest, but on the wetter soils. 

 They are somewhat shorter than the 

 hemlocks, have a heavy taper, and 

 reach dimensions at maturity of about 

 4 to 5 feet in diameter. 



The scrub type, consisting of the 

 open stands of somewhat dwarfed, de- 

 fective trees and dense undergrowth, 

 occupies soils of poorer drainage than 

 the hemlock type but better drained 

 than those occupied by muskegs. This 

 type covers most of the million acres 

 of timber of marginal value previously 

 mentioned, plus additional great areas 

 that offer only a remote possibility of 

 attaining future commercial value. 

 The marginal stands of scrub may have 

 from 5 to 10 cords or even more of 

 pulpwood an acre over large areas, but 

 the amount of the wood defect to be 



802062 c 



eliminated and the dense underbrush 

 and moist ground to be encountered in 

 logging give the material a distinctly 

 negative stumpage value at present. 

 The muskeg, with a tree growth lim- 

 ited to a few scattered and gnarled 

 hemlocks and cedars, is definitely a 

 nontimber type. Any future economic 

 value of Alaska muskegs lies in their 

 peat deposits and not in their timber. 



The main objective in the manage- 

 ment of the Tongass National Forest 

 is to bring all resources of the forest 

 land into use and to make them con- 

 tribute in the greatest possible degree to 

 the needs of the Nation and the devel- 

 opment and maintenance of the econ- 

 omy of southeastern Alaska. First, the 

 timber resource is to be made the basis 

 for permanent forest industries to be 

 established in the region. Second, full 

 use of all other resources, including 

 recreational features, the water-power 

 sites, minerals, and potential agricul- 

 tural lands, is to be encouraged. 



The timber inventories and studies 

 of tree growth that have been made on 

 this forest to date indicate that a rota- 

 tion of 80 to 85 years will produce the 

 most wood of good quality per acre per 

 year and that removing the present vir- 

 gin stand over that period of time will 

 permit the cutting of approximately 

 one billion board feet of timber a year. 

 This volume is sufficient to make at 

 least a million tons of chemical pulp, 

 plus considerable quantities of high- 

 grade lumber and plywood. 



Western hemlock and Sitka spruce 

 form an excellent forest type for the 

 production of pulpwood. The hemlock 

 is shade enduring and the spruce light 

 demanding, a combination which re- 

 sults in a dense stand per acre. Both 

 are fair to rapid growers and produce 

 high total yields, and both woods have 

 good pulping qualities. The hemlock- 

 spruce forests, except in a few small 

 areas, do not lend themselves to the 

 practice of selective logging, the system 

 of cutting under which trees of all ages 

 are grown in one stand and individual 

 trees are selected and removed as they 

 reach maturity. Both the hemlock and 



