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  1. Cottonwood and Balsam Poplar | Geophysical Institute

    2025年9月25日 · 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

    2025年9月25日 · 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. More on Why Tree Trunks Spiral | Geophysical Institute

    2025年9月25日 · 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 …

  4. The largest black spruce in Alaska | Geophysical Institute

    2010年8月16日 · 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 …

  5. Trees as Earthquake Fault Indicators | Geophysical Institute

    3 天之前 · 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 earthquakes …

  6. Witches' Broom | Geophysical Institute

    2025年9月25日 · Witches' broom on spruce trees is caused by a rust disease (a kind of fungus disease). The rust lives on the spruce tree throughout the year. Each spring, small yellow …

  7. The majesty and mystery of Alaska yellow cedar | Geophysical …

    2021年7月23日 · A tree near one of our campsites had a crack at its base through which we could pass the folded saw. Yet the tree was still alive, with just one rope of cambium — the outer …

  8. Maverick red aspens in a world of gold | Geophysical Institute

    2014年9月11日 · The parent tree replenished its leaves’ chlorophyll as the sun faded them like colored paper left on the windowsill. The tree's autumn refusal to ante any more chlorophyll …

  9. Burls - Geophysical Institute

    2025年9月25日 · Burls, spherical woody growths on the trunks of spruce, birch and other trees, are commonly found throughout wooded parts of Alaska.

  10. Trees for a Cold Climate | Geophysical Institute

    1993年4月1日 · 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 …