Thursday, August 26, 2010
It’s hard to believe that autumn is just around the corner, but it is. Fall is quite possibly the most spectacular time to visit Aspen, depending on who you ask of course. The crisp air, changing leaves, and snow-kissed peaks all combine to form an incredible display of natural beauty. While the leaves won't be changing for about three weeks or so, we have had many inquiries about fall foliage and September is already shaping up to be a very busy month for us as a result. So in today’s post, we would like to elaborate on fall foliage. The following is a simplified explanation of why plants change colors in the fall. There are three pigments responsible for the beautiful colors we are blessed with every fall. The first pigment is chlorophyll, which is responsible for plants’ green color. The second is called a Carotenoid, which is responsible for the yellow, orange, and brown colors. The third and final pigment is called Anthocyanins, which is responsible for such disparate hues as the red in apples to the dark blue in blueberries, and of course a whole range of colors in the leaves of plants. Chlorophyll and Carotenoids are present in the chloroplasts of leaves throughout the year, while Anthocyanins are only present in the fall when they are in the presence of bright light and an excessive amounts of sugar that has been produced and accumulated via photosynthesis during the spring and summer months. During peak growing season chlorophyll undergoes repeated periods of production and degradation in order to make sugar. The continuous presence of chlorophyll is what is responsible for plants’ green color. In the fall as nights become progressively longer, the production of chlorophyll slows down and eventually stops. As the presence of this dominant pigment (chlorophyll) is reduced, the Carotenoids and Anthocyanins are able to literally show their true colors. A warm and wet summer with cool, sunny, and dry fall days leads to the most spectacular show of color. Moisture, temperature, and sun are the most variable portion of the fall foliage equation due to the infinite ways in which the three can be combined. In sum, what is most responsible for the change in colors is the shift in the concentration of pigments as chlorophyll production slows down and eventually stops due to progressively longer nights. This allows the pigments Carotenoids and Anthocyanins to become “unmasked” revealing a spectacular display of color. There is no better place than Aspen to witness the transition of plants from their flourishing summer green into their endless spectrum of yellows, oranges and reds that triumphantly lead them into their winter slumber. Leaves tend to peak in the Aspen area at different elevations in mid to late September. The leaves change first at tree line and work their way down as fall progresses. Come and visit us and we will tell you all the best places to take pictures that are certain to make all of your friends and colleagues jealous!