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  1. Cottonwood and Balsam Poplar | Geophysical Institute

    Jun 12, 2025 · 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 …

  2. Northern Tree Habitats - Geophysical Institute

    Jun 12, 2025 · Interior Alaskan forests have only six native tree species: white spruce, black spruce, quaking aspen, balsam poplar, larch (tamarack) and paper birch. Northern Canadian …

  3. Witches' Broom | Geophysical Institute

    Jun 12, 2025 · In interior Alaska and some parts of Canada, witches' broom (an abnormal outgrowth of branches of the tree resembling the sweeping end of a broom), is commonly …

  4. Tree Rings and History | Geophysical Institute

    2 days ago · 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 …

  5. Trees as Earthquake Fault Indicators | Geophysical Institute

    Jun 12, 2025 · Then using tree ring dating methods, it may be possible to date earthquakes occurring before historical records were kept. The ability to identify and date very large …

  6. More on Why Tree Trunks Spiral | Geophysical Institute

    Jun 12, 2025 · 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 …

  7. The Kodiak Treeline | Geophysical Institute

    Jun 12, 2025 · 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. …

  8. The largest black spruce in Alaska | Geophysical Institute

    Aug 16, 2010 · The tree leans uphill, and its trunk is 45 inches around. When I hugged it, I could barely clasp my hands together. The largest black spruce in Alaska is a lucky tree, because its …

  9. Trees for a Cold Climate | Geophysical Institute

    Apr 1, 1993 · Back on the ground, I did a little research on why so few tree types grow naturally in the neighborhood. Winter's extreme cold easily eliminates some tree species hardy elsewhere. …

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

    Jun 12, 2025 · 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 …

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