2025年3月13日 · The best lodgepole pine races are faster-growing than the local spruces and larch planted in the same area; but again, only time will tell if the advantage will remain with the pine. Why take a chance with exotics, when native trees have proven their ability to survive? Several reasons prompt testing of foreign tree species.

2021年6月18日 · The two-acre exotic tree plantation is part of a much-larger “boreal arboretum” on the UAF campus, which mostly consists of native spruce, birch, aspen, poplar and willow trees. Having borrowed the key from a researcher with UAF’s Agricultural and Forestry Experiment Station, Woodward has invited me to join him inside the chain-link fence.

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 …

2025年3月27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.

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13日 · One of many Christmas pleasures is the aroma of a freshly cut tree. Both spruce and pine have it. So do cranberry fields in the morning, orange peelings, and some paint thinners. The substances known as essential oils are responsible for these odors.

1993年4月1日 · Yet the pine species have raced our way, at a couple hundred meters a year, for the last 12,000 years. They have adapted and evolved as they've come, so even without human- induced climate warming, they should be along shortly. Perhaps they'll make it over the border in time for Alaska's bicentennial---if they hurry.

2025年3月27日 · Another dating method is referencing ring patterns in earthquake killed trees to those of trees that have lived through the event and which can be accurately dated. Trees along faults often are killed by drowning because the faults tend to collect normal drainage water. In some instances, there are widespread tree kills caused by general ...

2015年11月19日 · Using a "mass-attack" strategy, beetles use sheer numbers to overwhelm old-growth trees like the ones in Berg's yard. Tree by tree, the Kenai Peninsula became a graveyard of whitish spruce snags, about 30 million of them. But the death of the old released the young spruce, suddenly enriched with more sunshine and water.

2024年6月12日 · None of those identification methods, including Zwieback’s, can determine the cause of an individual tree’s death. The likelihood of beetle infestation is surmised because of its well-known presence and the damage already caused. Zwieback’s method combines the efficiency of automation with the detail of high-resolution satellite images.