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 ...
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.
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 squirrel pups. Over the years, those squirrels have taught Boutin and his colleagues many things, including an apparent ability to predict the future. Boutin, of the University of Alberta in Edmonton, was ...