Fall in the Eastern Deciduous Forests has to be one of the most dramatically beautiful events of any ecosystem in the world. With fall, a series of events take place that begin the transition to winter. Thick green of late summer, growing from canopy to forest floor, slows with shortening daylight and cooler temperatures. With less daylight, chlorophyll which normally colors leaves green begins to breakdown. As it breaks down, colors normally hidden by the green begin to express themselves. Bright yellows from carotenoids in ashes, reds from anthocyanin in maples, and browns from tannins in oaks. Red and yellow pigments breakdown even further and the leaves turn brown and fall to the ground. These leaves form a layer of mulch across the forest floor, insulating the ground through winter, protecting plants, seeds, and animals from extreme temperature changes. In spring, the leaves decay returning nutrients to the soil and fertilizing plants and trees in spring.
|Normally green leaves gain their color from chlorophyll. But when daylight decreases in the fall, chlorophyll breaks down and other pigments are shown, changing the color of leaves.|
|Hickory leaf colored yellow by the presence of carotenoid pigments.|
|Maple leaf colored orange by anthocyanin pigments.|
|Acorn and oak leaves. The tan coloration of the small oak leaf above is caused by tannins oak leaves contain.|