November 15, 2014

Why do leaves change color and fall off trees?

This is a question I would always ask myself as fall came around, but I would never worry too much about the answer. As I was walking around my neighborhood this week all the leaves on the road got me thinking again of this old question. So I thought this time, why not find out the answer already! Before I actually got to the answer I observed a small bush close to my house that had exactly what I was looking for. This bush had a mixture of different colored leaves with some already fallen off.

       

                                                   

As you can see the leaves on this bush were originally green but the fall season slowly turned them yellow. So I made my own hypothesis, maybe the leaves were changing color because they were dying. I thought of this because, why would a strong leaf change color and fall off of its lifeline if it still has energy to hold on. The only reason it would fall and change color is because its weak and just wants to let go. Just like a human, we’re strong and try to hang on but when we get sick and weak our skin color doesn't change but it does get paler than usual.

After observing the bush and its leaves for five more minutes I finally looked up the answer to my question. Why do leaves change color and fall off trees?

-“When leaves appear green, it is because they contain an abundance of Chlorophyll. There is so much chlorophyll in an active leaf that the green masks other pigment colors. Light regulates chlorophyll production, so as autumn days grow shorter, less chlorophyll is produced. The decomposition rate of chlorophyll remains constant, so the green color starts to fade from leaves.”

-“When winter approaches, our part of Earth receives less sunlight, and the air grows colder. When these changes happen, trees prepare for winter. Trees that drop their leaves seal the spots where the leaves are attached. Then fluids cannot flow in and out of the leaves, which change color and fall off.”

So just like the leaves we can fall off of our lifeline at a certain point in our lives but we will always have a chance to come back and be ready for it to happen again because it's just "Human Nature".

Work cited: 

Helmestine, Anne Marie. "Why Do Leaves Change Color in the Fall?" About.com, 1 Jan. 2014. Web. <http://chemistry.about.com/od/howthingsworkfaqs/f/fallleafcolor.htm>.

"How and Why Do Leaves Fall off Trees?" Highlight Kids. Web. <http://www.highlightskids.com/science-questions/how-and-why-do-leaves-fall-trees>.