𝘕𝘰𝘷𝘦𝘮𝘣𝘦𝘳 12, 2021
Since yesterday was a bank holiday (Veterans Day) we decided to take a drive up the mountains to see the fall colors among the leaves. Two different friends of Melissa’s who live in the mountains recently commented on how beautiful they were. We started our journey at an elevation around 450 feet (138.5 meters) and over the hour-long drive climbed to the top of Blue Mountain at an elevation of 2687 feet (819 meters). That meant while the leaves had not begun to turn in our area, they did as we climbed. Some areas at the top of the mountain had even dropped their leaves after the storms we have had this week. We ate lunch at a table overlooking the beautiful leaves that adorned the trees on the mountain slope below. We were glad we had made it to the leaves in time.
When I looked online, I found there are three main things that give leaves their color. These are the chlorophyll (green) which is necessary for photosynthesis, the carotenoids (carotene and xanthophylls) which produce the orange and yellow colors (role not entirely understood), and the anthocyanins which give the shades of red and purple. During summer the plant continually produces chlorophyll to aid production of glucose, and this sugary sap is what feeds the tree. As the day length decreases in the fall, the tree gradually starts to decrease the production of chlorophyll, causing the veins to the leaves to close off. What is left in the leaves is the carotenoids and any produced anthocyanins. Anthocyanins are produced by glucose trapped in the leaves. These sugars break down in sunlight and produce the red and purple pigments. Depending on the species of trees and other environmental factors, we end up with a dazzling display of leaves.
While most trees will not leave much glucose in the leaves before completely closing the veins, some do. The formation of anthocyanin pigments from glucose left in tree leaves is somewhat of an oddity in nature. It is not known why these trees waste food in the leaves and wasting produced food is rare in nature. Some botanists believe it helps the trees keep the leaves longer as the anthocyanins lower the freezing point of the leaves. Others think it is because when the leaves with the anthocyanins fall to the ground and are composted into the soil it helps prevent certain other plant species from growing where the leaves fell. This makes sure the tree does not have later competition for nutrients in the soil around the tree. It also makes for great fall displays of leaves.
𝗧𝗵𝗼𝘂𝗴𝗵𝘁𝘀: During High School and entering college I planned on becoming a wildlife biologist and my Senior year in High School and Freshman year in college focused on biology and science courses. I found that while I was very good at science and biology, that did not include chemistry. Having struggled through the first two courses and still facing Organic Chem, I changed goals and graduated in sociology and anthropology. I have come to realize that like the different leaves, each of us are blessed with different gifts and potential. My niece is good at Chemistry and that was her degree major. I drifted into the study of people and relationships and that has been my focus. While I still love science, the intricacies of chemistry are still beyond my grasp. Like most in the US, I will never truly understand the chemistry behind the vaccines (smallpox, diphtheria, polio). I have gladly received them all as the risk of disease outweighs the rare likelihood of side effects. I am not sure why this is different with covid. Follow the science. Change is coming and it starts with you.