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  1. Northern Tree Habitats - Geophysical Institute

    2025年12月18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 forests have all …

  2. Cottonwood and Balsam Poplar | Geophysical Institute

    2025年12月18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 giant …

  3. More on Why Tree Trunks Spiral | Geophysical Institute

    2025年12月18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 speculation here: …

  4. Burls and Human Cancer | Geophysical Institute

    2025年12月18日 · Photograph of a section cut from a tree with 5 burls that simultaneously grew at the same level on the tree. Annual growth rings can be followed around the tree trunk at center and into …

  5. Trees as Earthquake Fault Indicators | Geophysical Institute

    2025年12月18日 · 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. Burls - Geophysical Institute

    2025年12月18日 · Burls, spherical woody growths on the trunks of spruce, birch and other trees, are commonly found throughout wooded parts of Alaska.

  7. The secret life of red squirrels | Geophysical Institute

    2024年11月27日 · Stan Boutin has climbed more than 5,000 spruce trees in the last 30 years. He has often returned to the forest floor knowing if a ball of twigs and moss within the tree contained …

  8. Witches' Broom | Geophysical Institute

    2025年12月18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 pustules …

  9. Kannada pocket guide for Common Avenue trees of Karnataka

    A citizen friendly pocket-sized book in Kannada describes commonly found avenue trees, filling the paucity of such resources in the local language while also

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

    2023年5月25日 · 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 …