The aspens have been getting closer to peak colors every day and it certainly seems like more orange leaves are out this year. It is not just about the aspens. Colorado mountains are dominated by aspens for color changes, but look up high.
Above timberline where no tall trees grow, the colors are amazing this year. The alpine zone has primarily perennial plants. It is very hard for annuals to survive at high elevations.
These perennials have many adaptations to survive. Indeed, there are trees in these tundra elevations. The willow trees adapt to any elevation growing closer to the ground up above timberline and are turning a beautiful bright yellow this year.
There are a couple different species of willows that are smaller the higher you go. One you will find is just growing along the ground, not up more than an inch or two above the ground. If you look closely, you can pick out the branches spreading out right on the ground, where they can survive.
All the alpine plants have developed many clever adaptations to survive the long winter, high winds, and long, dry periods. Growing low to the ground is a consistent adaptation, while fuzzy hair-like growth on leaves can be protective and waxy leaves can help preserve moisture. Yes, leaf peeping is popular and there is always much speculation on peak aspen colors.
This year, I think the tundra might be beating the aspen colors. Above timberline, the colors are often muted unless you are looking up close at individual plants. This year, the high elevations of our mountains have been the greenest I can remember.
It wasn’t until we got that first snow on most of our highest mountains that the green began to fade. Now, after many nights below freezing above 10,000′, we are seeing some of the brightest orange and red and yellow colors up above timberline. These tundra plants have had a very prolific summer, with the rain falling off and on throughout the summer.
Most people say this summer has produced the tallest and the most wildflowers ever seen. Usually, we have some long dry periods and more extreme fire danger. Luckily for us, we have had more limited high fire danger than usual and, along with that moisture, high-elevation plants have been growing more leaves, more flowers and more food for the pikas to store away for the coming winter.
Along with happier, leafier alpine plants, the plants have more leaves to turn yellow, orange and red and show off from a distance covering the alpine zones. A more normal summer would have left many of these plants turning brown by now and not showing off such bright colors. Nature will always surprise us and give us mysteries to solve.
Leaf colors are created by pigments at all elevations. Chlorophyll is necessary for photosynthesis and gives the green color that allows for plants to use sunlight to manufacture sugars for food. These sugars must be stored for the winter dormant season.
The loss of chlorophyll in the autumn months allows for the yellow, orange and red pigments. The darker red that seems so predominant this year is caused by later-formed anthocyanin. The color in some favorite red foods, like cranberries, cherries and strawberries is also from anthocyanin.
Up above tree line the colors can’t hide behind other trees, so looking at the tops of our mountains can reveal more colors than just looking at a forest. While you are enjoying our colors of the season, don’t forget to look up high to see more red and orange this year..
