July 27 (UPI) -- New research suggests trees aren't immortal. Even the world's most ancient trees will eventually die, according to a new study published Monday in the journal Trends in Plant Science.
Surveys of some of the oldest trees on Earth, including ginkgoes, have failed to turn up evidence of senescence, or aging, in centuries-old trees.
Just because signs of senescence are imperceptible to humans, however, it doesn't mean they're nonexistent -- or that a tree is immortal -- researchers say.
"When we try to study these organisms, we're really astonished that they live so long. But this doesn't mean that they're immortal," study author Munné-Bosch said in a news release.
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"They live so long because they have many mechanisms to reduce a lot of the wear and tear of aging," said Munné-Bosch, a professor of plant physiology at the University of Barcelona in Spain.
The most resilient and ancient trees have evolved a remarkable ability to delay and minimize the effects of aging, but research suggests they are not immune from physiological stress associated with senescence.
"They have limits," said Munné-Bosch. "There are physical and mechanical constraints that limit their ability to live indefinitely."
Because especially ancient trees are quite rare, studying them is difficult. Finding a tree dying from the effects of aging is even more rare, as trees are much more likely to perish from other causes -- including wind, disease, fire and humans.
"They don't have to worry about senescence because they have other things that worry them more," Munné-Bosch said.
According to the latest paper, because the lifespans of the world's longest-living trees are so enormous, evidence of senescence manifests on timescales much greater than the lifespans of scientists.
Even if trees aren't immortal, Munné-Bosch suggests the study of their strategies for delaying and managing the aging process is important.
"We have a lot to learn from them. For instance, aspects of regenerative medicine are based on mechanisms that have already evolved in trees," Munné-Bosch said. "Although aging is not a universal process, the knowledge that even the oldest species cannot live forever means that 'maybe we are not as different as we think.'"
