“Young adult Western literature” is where I read about aspen trees for the first time.

As I grew up in Paris, France, I had never seen an aspen in real life, but I was an avid reader – and those books took me to new territories beyond my own borders. I was entertained by the endless conflicts between cowboys and Indians, but I really enjoyed the descriptions of the majestic sunsets over the vast plains, the smell of the campfire and the pot of beans cooking on that fire, which would be followed by the moon rising, the glowing embers and the coyotes howling in the night. I could smell the fire and the beans, and somehow the “quaking aspens” were often part of the scenery.

How can a tree tremble? This term came back to puzzle me.

I saw my first aspen in the hills above Santa Fe. I had never seen one in person, but I recognized it right away. Yes, it was trembling; the leaves were in a gentle motion while all of the other trees around were still. I came close to hugging this tree – but I have learned to calm myself down, and instead I laid my hand down on the smooth, white trunk. (But perhaps hugging the tree would have been OK in Santa Fe?)

Why do the leaves quake at the slightest wind? The petiole – that is the stem of the leaf – is long, flexible and flat, so the wind easily makes it move.

I just came back from visiting Zion Canyon and Bryce Canyon and saw many glorious forests of aspen, shining golden yellow in their fall glory, as bright as a bouquet of marigolds in the sun.

When I found out the aspen became Utah’s state tree on May 13, 2014, I knew I had to write about those gorgeous trees.

As I was taking way too many photos, I noticed something strange about those aspen forests. One group of many trees would be in full foliage while a group just next to it would already have lost its leaves. What was going on? I found the explanation on a marker on Route 12, one beautiful scenic road that goes through some of the most isolated parts of the U.S.

One aspen tree forms a colony through a network of roots that sprout into additional trees. Each colony is a clone of the first tree, propagating through a single root structure.

To make things more complex, aspen are either male or female, so the whole colony is either male or female. Each tree has the same characteristic. So if a clone starts to turn yellow early in the fall, the whole colony will start changing color at the same time – but that might be at a different time from the next colony.

I learned there is a colony of aspen in Utah affectionately called Pando. It is the heaviest living organism on earth, weighing an estimated 6 million kilograms, and also the oldest at about 80,000 years old.

Aspen have seeds in cottony fluff (they are from the poplar family) but they rarely reproduce through those seeds. Large stands of either male or female aspen make pollination difficult, so reproduction is mostly made by the roots.

That gives them another advantage in case of fire. The trees will burn in a forest fire, but the roots are not touched, and new sprouts come out soon. Fire is helpful: Aspen do not grow well in the shade, but young saplings will grow quickly in a burnt landscape.

They have had an increased popularity with the forestry services because they grow fast and they regenerate from sprouts, so they do not need to be replanted after harvesting.

Aspen wood is white and soft, but it does not burn well, so it is used to make matches and paper. It is a light wood, so it is used for furniture, boxes and crates. Shredded aspen is also used for packing and stuffing. It is used for animal bedding because it does not cause respiratory ailments like pine chips or juniper can.

Aspens were used by the pioneers to build log cabins and dugouts.

I was interested to read that the bark contains a substance used by the Native Americans and the pioneers as a substitute for quinine.

Also, it seems the leaves can be a source of food for caterpillars, moths and butterflies. (Lepidoptera feed on poplars.)

The elk also eat the bark and make marks on the trunk by pulling the bark with their front teeth. Aspens are usually found at higher elevations of 5,000 to 12,000 feet. They are deciduous and need a cold winter to survive.

In 1996, people started to notice that aspen forests were dying. In 2004, many scientists started to look for the reasons. They concluded that many animals were eating the young sprouts – cattle, deer and elk. The young conifers were left alone by these animals (not tasty, I guess), and the conifers were taking over the space. On the other hand, the pine beetles were killing the conifers, so that gave the aspens a chance to grow later.

One of the big problems was the many years of fire suppression, as wildfire helps the growth of aspen groves. This policy is changing, so that might also give a new chance for aspens to recover.

We will see what the future brings, but this tree is one of the most beautiful trees, and seeing them in their fall glory of gold is always a moment to savor.

Fall is truly a beautiful season. The cool weather felt good. It might be time to build a fire and cook those beans while watching the sunset.

Can anybody bring a guitar?

Evelyne Vandersande has been a docent at the Placerita Canyon Nature Center for 28 years. She lives in Newhall.