Looking for fall colors? Take a trip to treeline. The tundra plants are actively making the transition, leaving us to marvel at the complicated chemistry and stunningly beautiful results. The sedges and rushes have turned to rich amber as the green chlorophyll breaks down in its narrow leaves.
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.
P.S. I had a recent inquiry about a "friendly" dark gray and white bird found on a hike in the White Mountains. The bird in question is no doubt what we call a Gray Jay, also known as a "Camp Robber or WhiskeyJack". They are known as opportunists, taking advantage of any available food source, including hikers' gorp or trail lunches. There are many popular view points that seem to have their resident gray jays waiting for a scrap. In a few place gray jays have become pesty since hikers are often intrigued by these seemingly tame birds and offer gray jays all sort of M&M's and other treats if they will swoop down and pick it off an outstretched hand. Left to find food on their own gray jays will eat insects and seeds. Birds in this family Corvidae, are known for storing extra food and gray jays have a special gland that produces a sticky salvia which it uses to fasten food items to tree branches, far above any possible snow cover. As year round residents they don't migrate. See "The Sibley Guide to Bird Life and Behavior" by David Sibley for more information.
Photo credits: Mark Dindorf - Southern Presidentials 9/20/07; Nancy Ritger - Lakes of the Clouds 9/17/07