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  • Northern Tree Habitats - Geophysical Institute
    Interior Alaskan forests have only six native tree species: white spruce, black spruce, quaking aspen, balsam poplar, larch (tamarack) and paper birch Northern Canadian forests have all of those, plus jack pine, balsam fir and lodgepole pine Since northern Canada and interior Alaska share the same grueling climate and extremes of daylength, why are the Canadian tree species absent from
  • Tree Rings and History | Geophysical Institute
    A tree's age can be easily determined by counting its growth rings, as any Boy or Girl Scout knows Annually, the tree adds new layers of wood which thicken during the growing season and thin during the winter These annual growth rings are easily discernible (and countable) in cross-sections of the tree's trunk In good growing years, when sunlight and rainfall are plentiful, the growth rings
  • More on Why Tree Trunks Spiral | Geophysical Institute
    I eventually found a tree with a spiral lightning mark and it followed the spiral grain exactly One tree, of course, proves nothing "But why should the tree spiral? More speculation here: Foliage tends to be thicker on the south side of the tree because of better sunlight
  • Feltleaf willows: Alaska’s most abundant tree | Geophysical Institute
    The most plentiful moose food in the state — and probably Alaska’s most numerous tree — is the feltleaf willow, which was once called the Alaska willow As its name implies, the feltleaf sprouts canoe-shaped green leaves that feel fuzzy on the underside
  • Tree line changes on the Kenai Peninsula | Geophysical Institute
    The gradual change in tree line is one of many that people have noticed on the Kenai Peninsula in recent years The most obvious is the 1980s-to-1990s Spruce bark beetle invasion, during which the insects killed 30 million mature spruce trees on the Kenai and a wide swath of southern Alaska
  • Bark Beetles in Spruce Trees | Geophysical Institute
    Bark beetles attack spruce trees in early summer These brownish black beetles are common throughout Alaska and Yukon Territory where they kill trees by boring through the bark and feeding and breeding in the phloem (inner bark)--the thin layer of soft tissue directly beneath the bark If the beetles girdle the phloem, the tree will die since the phloem is the vital path that transports food
  • Visit to an exotic tree plantation in Alaska | Geophysical Institute
    The two-acre exotic tree plantation is part of a much-larger “boreal arboretum” on the UAF campus, which mostly consists of native spruce, birch, aspen, poplar and willow trees Having borrowed the key from a researcher with UAF’s Agricultural and Forestry Experiment Station, Woodward has invited me to join him inside the chain-link fence
  • Cottonwood and Balsam Poplar | Geophysical Institute
    The Klukwan giant holds the national record for black cottonwood diameter Its nearest rival, a tree near Salem, Oregon, does hold the national height record The Klukwan giant belies the belief that trees tend to get smaller the farther north one goes Both balsam poplar and cottonwood have value for fuel wood, pulp and lumber




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