Ancient trees provide a suite of ecological services to forests, as well as sustaining the entire tree population’s ability to adapt to a rapidly changing environment.
In this month's edition of Nature Plants, Chuck Cannon, PhD, director of The Morton Arboretum’s Center for Tree Science in Lisle, Illinois, reported that old and ancient trees (often more than 10 to 20 times older than nearby trees) radically change the overall genetic diversity and composition fitness of their surrounding populations.
Collaborating with scientists at Tuscia University in Italy and the University of Barcelona in Spain, he said the findings also indicate that these trees contribute evolutionary properties to forests that are vital to their long-term survival.
“We examined the demographic patterns that emerge from old-growth forests over thousands of years, and a very small proportion of trees emerge as life-history ‘lottery winners’ that reach far higher ages that bridge environmental cycles that span centuries,” said Cannon.
“In our models, these rare, ancient trees prove to be vital to a forest’s long-term adaptive capacity, substantially broadening the temporal span of the population’s overall genetic diversity.”
These trees, which comprise less than 1 percent of a population, given model conditions, contribute a vitally important amount of genetic and biological diversity to a forest’s overall population, documenting a broad range of historical environmental conditions that span hundreds or even a thousand years.
To put it simply, according to the authors, ancient trees have survived countless environmental changes over hundreds or thousands of years, and in turn, this genetic resilience is passed on to the forest. Moreover, these old trees sequester a disproportionate amount of carbon compared to typical mature trees.
They also learn and remember. And ecologist Suzanne Simard says they need our help to survive, inviting us to discover the wisdom of the forest. What captured the public’s imagination in her book Finding the Mother Tree was Simard’s assertion that trees are social beings that exchange nutrients, help one another and communicate about insect pests and other environmental threats. More...
Today's OGN Sunday Magazine articles