2025年2月6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2月6日 · 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. Prevailing winds, in most of the tree-growing northern hemisphere, are from the west.

2025年2月6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.

2025年2月6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 ...

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.

4 天之前 · 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.

2008年2月6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.

The tree, a dawn redwood, died of unknown causes about 55 million years ago. Williams, a researcher at Franklin & Marshall College in Lancaster, Pennsylvania, studies ancient forests all over the world, including the high arctic of Canada, which now only hosts willows as …

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1月23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 …