About 74 results
Open links in new tab
  1. Northern Tree Habitats - Geophysical Institute

    3 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

    Jan 22, 2026 · 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: …

  3. Tree Rings and History | Geophysical Institute

    Jan 22, 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. The secret life of red squirrels | Geophysical Institute

    Nov 27, 2024 · 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 newborn red …

  6. Trees as Earthquake Fault Indicators | Geophysical Institute

    Dec 18, 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 earthquakes occurring …

  7. Boreal owls perform by daylight | Geophysical Institute

    Mar 20, 2024 · The late biologist Dave Klein attached the nest box to a black spruce tree north of the University of Alaska Fairbanks ski trails many years ago. In search of a mate, the owl sings his …

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

    Jan 22, 2026 · 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 …

  9. Tree line changes on the Kenai Peninsula | Geophysical Institute

    Feb 6, 2008 · 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, …

  10. Orange trees in the Alaska Range | Geophysical Institute

    Sep 3, 2020 · It was a tree disease known as spruce needle rust, which infects only the current year’s needles of white, black and Sitka spruce trees. The orange powder is composed of millions of tiny …