Cottonwood and Balsam Poplar - Geophysical Institute
2024年10月31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.
The majesty and mystery of Alaska yellow cedar
2024年10月31日 · Learn about the enigmatic trees that can live for over 1,000 years and endure for hundreds of years after death. Find out how warmer winters, glaciers and other factors affect Alaska yellow cedar and what scientists can learn from its rings.
Burls - Geophysical Institute
2024年10月31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 largest black spruce in Alaska | Geophysical Institute
2010年8月16日 · Learn about the 71-foot black spruce champion that lives on the University of Alaska Fairbanks campus and how it was discovered and measured. Compare it with other Alaska state champions and the national record holder.
Tree line changes on the Kenai Peninsula | Geophysical Institute
2024年10月31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, during which the insects killed 30 million mature spruce trees on the Kenai and a wide swath of southern Alaska.
Feltleaf willows: Alaska’s most abundant tree
2023年5月25日 · Learn about the feltleaf willow, a common and versatile tree that provides food and habitat for moose, hares and ptarmigan in Alaska. Find out how it grows, reproduces and adapts to disturbed and sunny environments.
Witches' Broom - Geophysical Institute
2024年10月31日 · 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 seen on black and white spruce trees. From late fall through the winter, the brooms are dark brown or "dead"looking and are often mistaken for birds' and squirrels' nests.
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.
Trees as Earthquake Fault Indicators - Geophysical Institute
2024年10月31日 · 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 earthquakes occurring within the past thousand years is important in establishing earthquake risk and for predicting future earthquakes.
Northern Tree Habitats - Geophysical Institute
2024年10月31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.
- 某些结果已被删除