Gigapan trees 1

For my Gigapan assignment, I will be observing trees by the Upper Lake of Sweet Briar College's campus over the next few weeks. In this area, there are many types of trees including the Blue Ash, Chestnut Oak, and a Shumard Oak. As it gets closer and closer to fall, well actually it is fall already, the leaves on the trees will begin to change colors. Therefore, over the course of the next few weeks I will be observing and blogging about these three species of trees and how they are changing. No one knows exactly why trees change colors in the fall, but most scientists say it involves the glucose intake during photosynthesis. In the trees that change to red and purple, the glucose seems to get trapped after photosynthesis. Also, the cool temperatures of fall cause the glucose to change colors causing the reds and purples that we see. The brown colors of other trees is caused by wastes leftover in the leaves. Other factors of leaf color changing include the length of the nights and the intensity of sunlight. This causes the veins in the leaves to close off while cells form around the base of the leaves. This traps the sugars, such as glucose, inside the leaves causing it to change color. Eventually, this will also cause the leaves to fall off the tree. Some scientists also say that leaf color changing involves the anthocyanin pigments. They say that these pigments is what tints the leaves red, purple, and/or crimson. The yellows and gold colors come from the cartenoids, which are present year-round. Therefore, these colors never actually go away during the year. Right now, each of my three trees have not changed color and are still green.