The Colors of Fall

The changing colors of leaves is something that marks the yearly transition from summer to fall to winter and it's something that we've become so accustomed to that it sometimes passes by unnoticed. Although this process is familiar to everyone, why it happens might not be so commonplace. The leaves of trees are filled with pigments called chlorophyll and carotenoids and occasionally anthocyanins and these chemicals are responsible for the varying colors we see in leaves. Through the summer the green chlorophyl in leaves is photosynthesizing sunlight into sugars and covers up the carotenoids which range in color from bright yellows to oranges. Chlorophyll is constantly broken down and replaced during the warm season but as the weather turns cooler the sunlight diminishes and plants respond to that by creating less chlorophyll, revealing the carotenoids which turns the leaves the colorful oranges and yellows we associate with fall. Anthocyanins are responsible for the reds, purples, and crimson we see in fall which are also revealed by lack of chlorophyll but are not present in all plants. Anthocyanin production is also dependent on the weather so certain conditions create better and more brilliant reddish colors in fall. As the nights get cooler its harder for the sugar created in leaves to flow out of the leaf veins into the rest of the tree. Scientists have found that trees create anthocyanins to recover as much sugar as they can from the dying leaves. So during fall, warm days and cold nights create conditions conducive to the creation of anthocyanins, creating brilliant reds and crimsons. As beautiful and expected the fall colors are why these varying colors appear is not as common knowledge. When we take a closer look into the chemistry behind the changes, we find that pigments, which play an essential part of a plants survival, are responsible for the brilliant fall display