Fall is upon us as the leaves begin to change from green to brilliant hues of crimson, orange, and gold. The trees in Gunnison and Crested Butte begin to turn colors around mid-September through the end of October. However, with this year’s early surprise winter storm, which covered both Gunnison and Crested Butte with over a foot of snow in some regions, may have triggered the trees and shrubs to begin this process more rapidly than usual. The Aspen trees are by far the more common type of tree whose leaves change colors in the fall, but other native trees, such as the Narrow Leaf Cottonwood and the Gray Alder, are also going through the same biological processes.

What triggers these biological processes, you may ask? According to the U.S. Forest Service, in the section “Science of Fall Colors,” there are three main factors that contribute to the changing of the leaves in the fall. One factor is the length of the night. The leaves begin to lose their green vibrance as the nights grow longer and the days become shorter. With less sunlight available, the green-colored chlorophyll is converted into storable sugars to be used later during the winter months, essentially dying off and allowing for other pigment producers, such as carotenoids (yellow and orange) and anthocyanin (red), to show through; therefore, leaf pigment is another thing that influences the changing of the leaves. Lastly, the weather also affects the onset of autumn color changes. The most spectacular displays of color are more likely to happen when there is a long succession of warmer sunny days. So, this September’s two-day-long blizzard will most definitely have some effect on the trees changing and falling more rapidly.

Visit the U.S. Forest Service site for more information on the “Science of Fall Colors.”