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 of those, plus jack pine, balsam fir and lodgepole pine. Since northern Canada and interior Alaska share the same grueling climate and extremes of daylength, why are the Canadian tree species absent from ...
A very noticeable fall equinox feature in these parts is when deciduous tree leaves turn from green to yellow or orange or sometimes red, then fade and waft to the ground. Middle Alaska doesn’t have many species of deciduous trees: paper birch, aspen, willows and balsam poplar are all part of the dominant boreal forest here.
It is common for people in interior Alaska and corresponding areas of northwestern Canada to use the name cottonwood when referring to one widespread variety of deciduous tree.
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 and thin during the winter. These annual growth rings are easily discernible (and countable) in cross-sections of the tree's trunk. In good growing years, when sunlight and rainfall are plentiful, the growth rings ...
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: Foliage tends to be thicker on the south side of the tree because of better sunlight.
A 20-inch fossil palm leaf that once waved over a tropical forest in Alaska 45-60 million years ago. The fossil was found in rocks near the Malaspina Glacier. Photo from the U.S. Geological Survey, Dept. of the Interior