Why are leaves green and then turn different colors as they are going to fall from a tree?

The change of season is always very obvious because of the changes to the trees. According to each season leaves vary in different colors the reason behind this change of color is due to the chemical imbalances in the leaves. Leaves receive their nutrients through the process of photosynthesis, which involves using sunlight to convert water and carbon dioxide into sugar. Leafs are a certain color because of the leaves pigmentation. In leaves there are three pigments; chlorophyll produces a green hue, carotenoid creates the yellow, orange and browns, and anthocyanin creates a red color. In autumn there is less hours of sunlight and the temperature slowly drops. Trees respond to the changing conditions are start to produce less and less chlorophyll, and at one point the tree stops producing chlorophyll. At this point the carotenoid which is already present in the leaves, becomes visible and the leaves will start to turn an orange and yellow color. Anthocyanins are very receptive to temperature and cloud cover conditions, when there are a number of sunny autumn days with warmer nights the leaves will be more red that season. The cool nights of autumn being to deprive trees of their nutrients because sugar sap can’t flow through the leaf veins and down into the branches and trunk. Anthocyanin is a protein that is releases as a form of protection so that the plant can recover some nutrients in the leaves before the fall off. The Anthocyanin buys the tree time to drain the leaves of all the glucose before the separation layer is formed. The veins in the leaves being to constrict and a separation layer is formed at the base of the leaf stem. When the layer is complete the leave is separated form the tissue that connects it to the branch and it falls off.

One thought on “Why are leaves green and then turn different colors as they are going to fall from a tree?

  1. Michael I Barrett

    Nice post, Max. I finally understand why the leaves of trees change color in the fall! Don’t you think it’s weird that just tree leaves change color in the fall and not any other plant? Maybe it’s just me….

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