2026年3月26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 …

2026年2月12日 · 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 …

2026年3月26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: …

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 …

2008年2月6日 · 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, …

2021年6月18日 · The two-acre exotic tree plantation is part of a much-larger “boreal arboretum” on the UAF campus, which mostly consists of native spruce, birch, aspen, poplar and willow trees. Having …

3 天之前 · 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. In recent years, …

2026年3月26日 · Bark beetles attack spruce trees in early summer. These brownish black beetles are common throughout Alaska and Yukon Territory where they kill trees by boring through the bark and …

1972年7月10日 · Sunlight passing through minor apertures between tree leaves is focused like the rays in a pinhole camera (and, just as with a simple lens, the image is upside-down).

2004年2月26日 · Knowing that, forest managers might be able to anticipate an outbreak and plan tree harvests ahead of the beetles or try preventative measures that might work on small outbreaks, such …