|This image was taken above Alta Utah which was once a booming silver
mining town, and is now home to the Alta and Snow Bird ski resorts. Evidence of
Alta's mining past can still be seen on the mountains though the aspens and
pines are slowly reclaiming the mountain sides as their own.
In this shot some of the different colors that Quaking Aspens turn in the autumn are displayed. Autumn colors are controlled by a complex interaction of pigments, hormones, temperature, moisture, light, chemicals and genetics. Aspens in groups are usually all the same color and change color and drop their leaves with in a few days of each other because a group of Aspen is normally comprised of genetically identical trees. Aspens can reproduce by under ground runners making them genetically identical as well as by the more common reproduction plant reproduction method of seeding.
Technically a grove of Aspen trees may actually be just one organism. The largest known of these groups which is located in Utah is called Pando and some experts consider it to be the largest living organism in the world. Estimated to weigh in at 6,615 tons and possibly as old as 80,000 years old.
You can find more info on Pando here Pando on Wikipedia
While these groups of Quaking Aspen are much smaller then Pando I believe they hold their own in the color arena.