PRODUCTIVITY, POPULATION-STRUCTURE, AND SUBSISTENCE USE OF A WHITE SPRUCE FOREST IN THE KENNICOTT VALLEY, ALASKA

The dynamics of white spruce (Picea glauca [Moench] Voss) in a sparsel y populated Alaskan valley were examined for management of subsistence firewood and house-log harvest. Site index, disturbance history, curr ent productivity, and population age structure of white spruce were de termined at 26 sites on five landform units. Human residents were inte rviewed to characterize local harvest patterns. Site index averaged 59 and was not significantly different among landforms. Current producti vity, which ranged from 0.20 to 2.22 m(3)/ha/yr, was reduced by a 5-ye ar old spruce beetle outbreak that killed up to 42 percent of the stan ding volume in some stands. Forests consisted of even-age stands initi ated by deglaciation (20% of study area), wildfire (13%), and anthropo genic fire (26%), and mixed-age stands characterized by small gap-form ing disturbances (41%). The latter stands exhibited old-growth charact eristics. A demographic model based on age-structure in the old-growth stands showed that current recruitment was too low to maintain curren t tree density under conditions of natural mortality, and that removal of live trees by selective harvest or beetle outbreaks will diminish tree density. Current annual firewood demand of 61.5 cords/year is ade quately supplied by beetle-killed spruce, but demand for live trees wi ll rise as beetle-killed trees decay and become unusable. Small commun ity wood-lots are suggested as a sustainable alternative to selective harvest.