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"Volume", a forest characteristic that describes the 

 structural variety of old growth, is critically important to 

 wildlife management on the Tongass National Forest. A stand's 

 "volume" refers to the amount of merchantable wood fiber in the 

 stand, and is generally related to the size, stocking density, 

 and species composition of the dominant trees. High-volume and 

 low-volume stands differ in their form, function, and appearance. 

 Not surprisingly, they also vary in their value to wildlife. 



Low-volume old-growth forests are characterized by a relatively 

 open canopy and productive understory. In the absence of snow, 

 these stands provide abundant food for wildlife such as deer. 

 Over a series of mild winters, these stands can sustain large 

 numbers of deer. 



The presence of snow, however, changes the situation 

 dramatically. Given deep snow, deer concentrate in high-volume 

 old-growth stands, where snow accumulations are substantially 

 lower, physiological energy costs are reduced, forage is more 

 available, and chances of survival are improved. High-volume 

 stands are the key winter range of Sitka black-tailed deer under 

 limiting snow conditions. 



High-volume old growth occurs most commonly at lower elevations, 

 along streams, on alluvial flood plains, and on river terraces 

 and deltas. It commonly is found in a narrow band along the beach 

 fringe, or on the toe slopes at the base of steep hillsides. 

 These locations make it important habitat to many wildlife 

 species dependent on riverine or saltwater systems. Such species 

 include the bald eagle, which nests along the beach fringe in 

 large, old trees; river otter and other furbearers that associate 

 with the beach and riverfront habitats; and the brown bear that 

 forages along the beach fringe in spring and uses streamside 

 habitats in late summer when salmon are spawning. Sitka black- 

 tailed deer are found throughout high-volume old growth during 

 periods of deep winter snow. 



Management Implications to Wildlife on the Tongass National 

 Forest 



Several wildlife species have been shown to be adversely impacted 

 by cutting old-growth forests in Alaska. Clearcutting replaces 

 diverse, uneven-aged stands having high habitat value, with even- 

 aged second-growth stands of low diversity and low value for many 

 wildlife species. Based on present knowledge, it is not possible 

 to significantly enhance second-growth forests for wildlife 

 species such as bald eagles, brown bears, river otters, and other 

 furbearers. 



