Growth of Historical Sitka Spruce Plantations at Unalaska Bay, Alaska

摘要

Sitka spruce (Picea sitchensis) grew an estimated 37 cubic feet of stemwood per acre per year in remnant World War II plantations on Amaknak Island and 38 cubic feet of stemwood per acre per year in an early 19th century grove on Expedition Island, 520 miles southwest of natural tree limits in Alaska. Trees in fairly dense plots on Amaknak Island averaged 7 inches in diameter at breast height (d.b.h.) and 21 feet tall on sheltered sites. The largest trees in the Expedition Island grove were 21.5 inches in d.b.h. and 55 feet tall. Growth and quality of Sitka spruce on productive sites near Unalaska Bay should be adequate for subsistence wood production, amenity of barren landscapes around homes and villages, soil enhancement, wind breaks, and wildlife habitat. Small outplantings of Sitka spruce and other species on sheltered sites from sea level to 820 feet (250 m) in elevation are recommended to determine tree limits, superior seed sources, wood yield, and forest association with native flora and fauna and to refine affore-station methods.