Sunday was glorious weather requiring a light jacket as the cool breezes gently blew throughout the day. It was a stark contrast to the smothering humid heat and screaming wind before the violent storm on Saturday evening. The rolling thunder, flashes of lighting and horizontal rain was remarkable in its terrifying velocity. Sunday reminded us there is calm following a storm… and Autumn arrived.
At last the trees are beginning their foliage show and it is promising to be a lovely one that we may enjoy until our first deep freeze. Although the following explanation will be a vast over simplification, it may provide insight into the foliage change. During the spring and summer the trees use their leaves to collect air and water to turn it into food. The process, called photosynthesis means ‘putting together with light’ so as the days shorten and daylight diminishes, the gathering process ends. The leaf is no longer necessary to the tree and begins its transformation providing breathtaking color for a brief moment in time.
The chemicals chlorophyll and carotenoids are present in the leaf cells throughout the growing season with chlorophyll making leaves the bright green color. As daylight decreases in autumn, chlorophyll production stops and the chlorophyll disappears. With the loss of chlorophyll the carotids, which have been there all along, become visible and display lovely yellow leaf color. Lastly the anthocyanins arrive and take center stage, ushering in the vibrant reds we associate with Autumn.
Anthocyanins, which are glucose (sugar), are singularly responsible for the brilliant hues of purple, crimson, and scarlet. They are a fickle lot, insisting on warm sunny days and crisp evenings to slow the closing of the leaf veins and trap excess sugar produced at this time… if the weather does not comply to their demand, lackluster reds are produced. Following this last exercise, the trees will toss their leaves so they may begin their final challenge.
Since shade and the foliage show are not all the leaves have to offer, their parting gift is perhaps the most important. As the leaves drift from the trees and collect below they continue to work by slowly decomposing. Over time this process adds nutrients to create a dark rich soil which nourishes the baby saplings as they grow to become forest giants like their parents. New research has proven that trees will provide a network of mutual care through intertwining roots and the adults will actually send nutrients to ill or immature trees to assure they live and thrive. The miracle of nature is always at work regardless of the season.