
Northern Tree Habitats - Geophysical Institute
Jun 26, 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 …
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 …
More on Why Tree Trunks Spiral | Geophysical Institute
2 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 …
Trees as Earthquake Fault Indicators | Geophysical Institute
Jun 26, 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 …
Tree Rings and History | Geophysical Institute
Jun 26, 2025 · 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 …
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. …
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 …
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 …
Alders go their own way in autumn - Geophysical Institute
Sep 10, 2015 · But one shrubby tree does not join the party. Alders remain a stubborn green. Many won't drop their leaves until long after the snow falls. This reluctance is one of the …
Tamarack -- Not A Dead Spruce | Geophysical Institute
Jun 26, 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 …