2025年4月3日 · Prevailing winds, in most of the tree-growing northern hemisphere, are from the west. Combine these factors, and the westerly wind pushing on the thicker south side of the tree, year after year, causes an asymmetrical wind loading which slowly twists the tree around in the observed direction.

2025年4月3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.

2025年4月3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.

2019年8月8日 · But geography defines species. The team found trees like the Flame of the Forest, Indian laburnum, Pongam, the Indian coral tree widely spread in dry regions of the state, along with the Gulmohar which has adapted to different climates. Whereas, in the wetter regions they documented trees like Champaca, varieties of Bauhinias and Bakula pushpa.

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:

2010年8月16日 · The tree leans uphill, and its trunk is 45 inches around. When I hugged it, I could barely clasp my hands together. The largest black spruce in Alaska is a lucky tree, because its neighbors to the north are gone, removed in the mid-1990s during the installation of a power line.

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.

2025年4月3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.

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.

2025年3月27日 · Photograph of a section cut from a tree with 5 burls that simultaneously grew at the same level on the tree. Annual growth rings can be followed around the tree trunk at center and into each of the burls. The rings show that the growth of …