The Tundra has Turned

Anthocyanins, the pigments giving us the reds, are beginning to accumulate in other alpine leaves such as Diapensia that has gone from a tight cushion of tiny green leaves to one of tiny purplish red leaves. The anthocyanin accumulates when sugars produced from photosynthesis in the leaf are unable to be transported to the roots for storage. These sugars attach to otherwise colorless pigments present in the leaf turning them to that unmistakable deep red purple hue.

What is so important about this change of color? The answer lies in the power of the sun and the importance of being ready for the next growing season. On a cool day we all know how nice it feels to sit in the sun. Well if you go put on a dark t-shirt you can absorb even more of the sun’s warmth and if you lie down on the ground out of the wind you might forget entirely how chilled you were a moment ago. Diapensia does just that. By growing low to the ground it is protected from the wind and dark reddish purple hue of the leaves in aids in absorbing the warmth of the sun. This is not so important in the fall and winter when the plant is dormant, but it is essential to the plant in the early spring. On the open windswept ridges where Diapensia grows, the snow depth can be relatively shallow with most of the snow getting blown off into surrounding ravines (hence the awesome skiing later in the spring). Diapensia now deep reddish purple absorbs the warmth of the sun melting it out of the snow earlier than many of the other surrounding plants.

So when you are soaking in those warm rays of sunshine on a cool fall day remember there are a few advantages to thinking about being prepared for spring!

Help us by recording your fall observations! AMC’ Mountain Watch Program is depending on hikers and observers to build our database of changing foliage. By monitoring when the colors change and corresponding weather factors we learn more about the changes in the mountain environment due to climate change. Download your datasheet today.