Christmas trees are dying. According to a recent essay, some conifers and other trees could live forever, and that more scientifically rigorous methods to determine their age and study their longevity are needed.
The authors of the review essay wrote that trees do not die as much as they are killed. Their killers are external factors. There is no evidence that harmful genetic changes accumulate over time or that trees lose their ability to produce new tissue.
Franco Biondi, an ecoclimatologist and tree-ring scientist at the University of Nevada, Reno, says that trees can live indefinitely. An external agent, biotic or abiotic, ends up killing them.
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In their book, Biondi and Piovesan write that tree killers include environmental threats, as well as human threats such as logging and fires. Their essay was published in a magazine.
Older trees are thought to store more carbon than younger ones, which is why tree longevity interests researchers. Climate change could be slowed by the persistence of trees, although rising temperatures caused by global warming can put a strain on trees, making them more vulnerable to environmental threats. The rings of old trees can be used as a record of climate history, with wider rings indicating better years.
Scientific models designed to study tree longevity have made incorrect assumptions, including the idea that shade tolerant late-successional trees, which are found in older ecosystems that have developed larger trees and a lot of shrub cover, are longer-lived. bristlecone pine trees are known to live in wide-open landscapes of the West and in the same environment for thousands of years.
The review essay was described by a researcher at the University of Arkansas as "excellent" and "comprehensive". He takes issue with the idea that trees can live forever. He says that the likelihood of trees being immortality seems unlikely. I like the idea. It is a romantic idea, but come on.
The hypothesis of tree immortality has grown popular in the past 20 years, as researchers continue to report having found little to no genetic evidence of aging in extremely old trees. He says this is one of the most important points. Evidence of aging could be out there, but not yet found.
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Adverse conditions, including the harsh, rocky landscapes populated by stands of bristlecone pines, can kill trees. The authors of the essay say that some disturbances are not bad for trees. In mountain regions, there are limited soil and tough climate conditions. It is as if trees that live a long time, up to thousands of years, abide by the axiom that which doesn't kill you makes you stronger. Many long-lived trees grew up in environments in which they had to compete for resources, such as water in dry stands of trees or sunlight in dense forests with leafy treetops or crowns.
The Great Basin bristlecone pine was dated using tree-ring analysis and found to be more than 5,000 years old. It would make it the oldest living thing on the planet. The age determination was made by the late Tom Harlan of the University of Arizona, who performed detailed analysis on a core sample taken from the tree in 1957. The estimate has not been confirmed by other researchers according to a list of extremely old trees created by Rocky Mountain Tree-Ring Research. The oldest living tree is a bristlecone pine called Methuselah, which is located in the White Mountains.
The review essay tackles a point about the uncertainty about the oldest living tree. Piovesan and Biondi write that some scientists use unreliable data and methods to estimate tree ages. They say that the most reliable age-determination methods are analyses of tree rings. Stahle agrees.
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Colorado blue spruces can live for hundreds of years after being chopped down for Christmas trees. The lives of ancient and culturally valued trees can't be cut short by practicing clear-cutting. More sustainable practices include harvesting only individual trees in a stand or forest while maintaining the cover each tree provides, the water quality it protects and the carbon it sequesters. Stahle says that they can do all these things. Good and bad actors are involved in the production of forest timber.
