Aspen trees are beautiful. But there’s much more happening underground with them that leads to their remarkable life.
One of the unusual things about Aspen trees is that the “tree” part that we view is
actually equivalent to an air root. Simply put, the actual tree lives underground and what we normally think of as a tree trunk is a type of root that grows upwards. Granted this is a simplification of the actual biological system. But it does explain why Aspens are usually found in clusters–all the trees (air roots) are connected to one large root system that is the actual core of the tree.
An Aspen tree system can be huge and long-lived. The Pando Aspen tree system in Utah is a single organism that weighs over 13 million pounds. That’s more than 14 loaded Boeing 747-8 airplanes. And the Pando tree system is estimated to be at least 80,000 years old.
While what we think of as a single Aspen tree (air root) can live to be 100 years old, the underground system lives on. As each air root in the system dies, it’s replaced by the underground system with another. And each air root’s death also gives life to other plants since sunlight is now able to penetrate to the forest floor where the dead air root once stood.
It’s both a beautiful and interesting system to encounter.
On a recent trip through Colorado, we hiked through a forest of Aspens at an altitude of 7,000 feet. Although we didn’t know the age of the Aspen system under our feet, if it too had been around for tens of thousands of years, what had this tree system witnessed?
Imagine if this forest was around 15,000 years ago when the Great Lakes were being
formed to the Northeast during the end of the last glacial period (ice age) and you get the sense of their longevity. During their remarkable lives, they live through a lifespan that’s completely alien to us.
The next time you see an Aspen, look down because you’re likely walking over a biological system that’s been around for a long time. It’s something that makes Aspens even more beautiful.