Yellow aspen trees

Photo: Rachel Jackson/500px

A treasure trove of gold

In October, the quaking aspen groves in June Lake, California, glow with vivid hues of yellow — and nothing sets off these colors like a crisp, clear autumn day.

While there are several species of aspen, only two can be found in North America: the bigtooth aspen in the eastern United States and the quaking aspen in the North and West. The quaking aspen is a tree of many names: trembling aspen, American aspen, golden aspen, white poplar, and even the nickname "popple." It is so-named because its leaves are attached to their stems by a thin, flexible stalk called a petiole, allowing them to move freely even in the gentlest of breezes. 

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Aspen leaves close-up

A close-up view of aspen leaves shows the flat, thin petioles that allow the leaves such movement. (Photo: Aidan Grey/Flickr)

The fluttering leaves of these 60-80 feet tall, white-barked trees are not the only thing that makes them unusual. The folks at the National Park Service go so far as to suggest that "it may be better not to think of aspens as trees" at all, as they grow from a large underground network of roots and sprout up via asexual reproduction, meaning there is no need for flowers or seeds, which appear later in the life of the aspen tree but aren't an effective way of reproducing.

An aspen grove is uniformly yellow because each tree is identical, part of the same organism and sprouting from the same system of roots. This solidarity lends itself to a long life. A clone of roots and its trees can survive for thousands of years — even longer than ancient Sequoias. In fact, a particular colony of aspens in Utah, called Pando, is considered one of the oldest living things on Earth at about 80,000 years old.

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Aspen trunks

The dark scars on an aspen's trunk usually signal that a deer has been by for a snack. (Photo: Johnny Adolphson/Shutterstock)

A peek underneath the white bark shows a green photosynthetic layer that keeps the trees fed throughout winter, and that doesn't just keep these trees thriving during cold and cloudy months — it also sustains populations of deer and elk as well.

Because of the way aspen trees sprout up, they will probably be around longer than many other species of plants and animals on the planet. However, certain factors — like overgrazing of the trunks by deer and of the roots by pocket gophers, plus drought and forest fire restriction — can be detrimental to these groves. Indeed, fire benefits aspen groves, wiping out the competition as the roots remain safely hidden.

Still, according to the National Park Service, aspen clones resist nearly every other manner of destruction — neither the elements (too much shade, diseased trunks) nor the efforts of foresters (chopping roots and spraying herbicides) can keep the roots from growing beneath the soil.

"Even after 100 years or more, the dormant root system will spring back to life, sprouting new trees once sunlight is allowed to reach the forest floor again," the National Park Service explains.

So it seems that these incredible, lively trees are here to stay. If you want to learn more, watch this entrancing video of a fluttering aspen grove in Rocky Mountain National Park:

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Anna Norris is an associate editor at Mother Nature Network. Follow her on Twitter and Google+.

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