This leaf is from a Sugar Maple Tree (Acer saccharum) native to the northeastern US and Canada as well as the Midwest. This tree was a favorite tree to plant along streets and in parks because it is fairly fast-growing and easy to transport. However, with the rise of air pollution, hardier trees like the Norway Maple were used instead. In the fall with a diminishing amount of daylight and drops in temperature, leaves stop their food-making process. In the spring and summer, chlorophyll in the leaves causes them to be green but in the fall trees stop photosynthesis through chlorophyll and begin to break the chlorophyll down causing them to appear yellow or orange. Trees break down chlorophyll and move it out of the leaves to conserve energy. In the spring when it is warmer, the tree will use this broken down chlorophyll to make more chlorophyll. This process is much more favorable than making new chlorophyll from scratch every year. You can see on the tips of this leaf that it is beginning to go through this process. In the fall other pigments like carotenoids and anthocyanins are produced also causing leaves to become yellow or orange.

Taken for JMU Technology & Design by Katja Wisch. All rights reserved. No usage without permission.