Cottonwood and Balsam Poplar - Geophysical Institute
2024年11月15日 · While poplar may grow to 100 feet high and two feet across, cottonwood can reach to 125 feet and be much larger in diameter. Cottonwoods three feet in diameter at breast height are common. To avoid both bending over and the flare near the tree stumps, foresters measure the tree diameters at breast height, hence the term breast height diameter.
Burls - Geophysical Institute
2024年11月15日 · Since the hardness of the wood is related to the rate of growth, the wood inside a rapidly growing burl is softer than the wood elsewhere in the tree. Nevertheless, it is hard enough to be sanded and finished into an attractive surface. An affected tree may grow a single burl or many; trees with multiple burls on both trunk and limbs have been ...
The majesty and mystery of Alaska yellow cedar
2021年7月23日 · Probably because of chemical compounds within the tree like nootkatin that emit the pleasant odor and tint the wood yellow, Alaska yellow cedar endures like no other tree in the state. In a 1997 paper on the endurance and possible usefulness of dead Alaska yellow-cedar trees, researchers Kent McDonald and Paul Hennon concluded it was good stuff:
Witches' Broom - Geophysical Institute
4 天之前 · Witches' broom on spruce trees is caused by a rust disease (a kind of fungus disease). The rust lives on the spruce tree throughout the year. Each spring, small yellow pustules appear on the new needles of the broom. A strong sweet odor, which is easily recognizable, usually accompanies the maturation of these pustules.
Mummified forest tells tale of a changing north
2011年1月6日 · The mummy trees of northern Ellesmere Island include a trunk of a pine tree four feet long and six inches in diameter. Each of the trees was at least 75 years old when it died. The ancient forest holds samples of the last real trees in the area before it became too cold and dry to support large plants, Barker said.
Northern Tree Habitats - Geophysical Institute
2024年11月15日 · They examined the present range of lodgepole pine and decided that the tree could survive in interior Alaska if given a chance. Lodgepole pine grows from southern California to the Yukon, in environments varying from rainy seacoasts to dry inland mountaintops, because genetically different strains have developed.
Trees for a Cold Climate - Geophysical Institute
1993年4月1日 · 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. Oak, ash, and elm endure occasional severely cold temperatures in the contiguous forty-eight states because they can produce chemicals that serve as natural antifreeze.
The Turkey and the Tambalacoque Tree - Geophysical Institute
1990年11月14日 · The problem was the decline of the tambalacoque tree, a once common and useful source of timber for the island residents. Only thirteen of the trees remained, and they were sickly specimens. Stanley Temple, a scientist in the department of wildlife ecology at the University of Wisconsin, Madison, found himself discussing the problem with ...
Feltleaf willows: Alaska’s most abundant tree
4 天之前 · 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 sprouts canoe-shaped green leaves that feel fuzzy on the underside.
Tree Rings and History - Geophysical Institute
2024年10月3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 and thin during the winter. These annual growth rings are easily discernible (and countable) in cross-sections of the tree's trunk.