Why do leaves change colors?


As I was walking to class I noticed the leaves have officially changed their colors, and it is fall officially. Fall is such a beautiful time of the year, especially here in State College. The fall is my favorite season of them all, mostly because of thanksgiving and football. After looking at the leaves that have changed colors and fell form the trees, it made me wonder what made them do that exactly. I know that they are dying, but how, is the question. After conducting some research about the topic, I figured out why they change colors exactly. It is  caused by something that is called Chlorophyll. Chlorophyll is what gives the leaves that green color that we all know.




The breakdown of this chlorine pigment , Chlorophyll, is how leaves change colors and die off. The change in temperature as well as the lack of sunlight or decrease. Due to this change, it allows red pigments and purplish pigments shine through. That is why we see alternate colors during the fall. Another change in leave characteristic that we can see change in the fall is that there is a  cell attached to the tree at a center of the leaf. The leaf then begins to tear away the tissue that supports the leaf, while this is happening the leaf falls off of the tree, but it does leave a scar on the tree itself. Not all trees lose their leaves though, the needle- trees stay green all year around.

Leaves fall, in the fall. The main reason that leaves fall off of trees is that the vegetation of trees would freeze if they did not, if this did not happen they wold become dead. Trees also “close of veins” that carry water and nutrients to the new cells ; preserving the trees.




Chlorophyll cannot occur without the incredible process that we know so well, which is photosynthesis.  I am sure that we all know what photosynthesis is, but this quick refresher will help  especially with understanding the relationship between photosynthesis and chlorophyll. Trees take water from the ground through its’ roots, while absorbing carbon dioxide. The trees give off oxygen, which is vitally important to us as humans. After water and Carbon dioxide is transformed into oxygen and glucose, glucose contributes to the energy of the trees. Chlorophyll  makes photosynthesis occur, which gives it the green color.


So the next time you are walking across to campus to your next class and see the leaves laying on the ground, you will know why the fall and change their color. It is because of the chlorine pigment, Chlorophyll. Due to the changes of temperature in the fall as well as decrease in sunlight the leaves lose pigment, and they fell off the tree.





1 thought on “Why do leaves change colors?

  1. jgb5274

    Your post caught my attention because I often wonder the same thing and how this could occur. It seems like something everyone should just know since it is so common but if you think about it there is an actual scientific process not many think to look into. If it is that easy for leaves to change color due to lack of sunlight and low temperatures, is it the same process for them to grow back as green again? Does the temperature just have to go up along with increased sunlight? http://northernwoodlands.org/outside_story/article/how-do-trees-know-when-to-leaf-out-in-the-spring After looking up the process of how they grow back I came across this article explaining how in the north the trees don’t die, they are just dormant because it is too cold to produce any leaves and the buds made from the previous summer come out in the spring forming the leaves, and like you said the chlorophyll makes them green.

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