20 hours ago
Climate Change and Trees (Part 1/2): If I was forced to choose my favorite season of the year, it would have to be fall hands down. Itās hard to beat the crisp air, comfortably mild temperatures, the not too early sunrises, and the not too late sunsets. But what I think we all love most about fall, is the mesmerizing, beautiful show the trees put on with the dazzling array of colors in their leaves. The green leaves we see during spring and summer, comes from a molecule called chlorophyll, which makes photosynthesis possible. This color shows that plants are alive, and they are absorbing CO2 and light from the atmosphere and turning it into glucose, the energy all living things depend on. The vibrant reds and oranges we see are not actually from the leaves changing colors before they drop, rather the leaves returning to their native colors as the green tint gradually disappears from the chlorophyll leaving, revealing the yellows and oranges that were always there hiding.
Trees drop their leaves in anticipation of winter. They stop absorbing light and CO2 and begin instead to store all the glucose they can internally, in order to survive the long, cold slumber. Trees can anticipate winter because of the shorter days and fewer hours of light, but they also pay attention to how often it freezes, counting until the temperature has dropped below zero enough nights in a row to know that they should probably start getting their affairs in order and prepare for the colder weather. They depend on their glucose reserves during winter for minimal energy as well as to keep the water inside their trunks from freezing, mixing the oily substance within every cell to combat the ice. Because they prefer to store as much energy as possible, if the temperatures arenāt consistently dropping below zero, trees will take the risk and continue to hang onto their leaves longer than normal in order to photosynthesize until the last possible moment, even after they have realized the days have become much shorter.
To be continued...