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  1. Northern Tree Habitats - Geophysical Institute

    5 days ago · 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 …

  2. More on Why Tree Trunks Spiral | Geophysical Institute

    5 days ago · 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 …

  3. Tree Rings and History | Geophysical Institute

    Feb 12, 2026 · 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 …

  4. Feltleaf willows: Alaska’s most abundant tree | Geophysical Institute

    May 25, 2023 · 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 …

  5. Tamarack -- Not A Dead Spruce | Geophysical Institute

    5 days ago · It is not possible to foretell if tamarack may some day become a commercial crop, but one thing is certain: the "spruce that dies" each fall has some unique qualities that make it a desirable …

  6. Bark beetles take Connecticut-size bite out of Alaska | Geophysical ...

    Feb 26, 2004 · Knowing that, forest managers might be able to anticipate an outbreak and plan tree harvests ahead of the beetles or try preventative measures that might work on small outbreaks, such …

  7. Visit to an exotic tree plantation in Alaska | Geophysical Institute

    Jun 18, 2021 · 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 …

  8. The Kodiak Treeline | Geophysical Institute

    5 days ago · Spruce trees planted on the islands by the Russians in 1805 are doing just fine and reseeding themselves naturally, although the total tree population hardly amounts to a forest. In …

  9. The Pinhole: Nature's Lens | Geophysical Institute

    Jul 10, 1972 · Sunlight passing through minor apertures between tree leaves is focused like the rays in a pinhole camera (and, just as with a simple lens, the image is upside-down).

  10. Cottonwood and Balsam Poplar | Geophysical Institute

    Apr 3, 2026 · 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 …