brg_admin | May 1, 2019 | 0
Musings of a Beaverton Teen: The Beautiful Wonders of Autumn Leaves
by Lani Garcia (11th Grader)
Fall is my favorite season of the year.
I love the crisp, rainy days, the rich smelling candles, and all the vivid colored leaves that line the streets when they fall. Which brings me to the question… why exactly do leaves fall? Do they serve a purpose for trees and the environment, or are they just a nuisance?
It turns out, there is a purpose.
Many actually. First, I will tell you how leaves fall. Each deciduous (leaf-dropping) tree can sense the days getting colder and shorter, which signals them to produce a hormone. A chemical signal gets sent out and, well, the tree takes it from there.
Why do trees get rid of their leaves?
If trees kept their leaves all year long, they would continue to provide the tree with nutrients they need to survive and reproduce. Evergreen trees (which don’t drop leaves) can outlast the cold, and that’s due to the fact that their foliage is covered in wax. Their cells also have antifreeze chemicals. The less fortunate deciduous trees, however, don’t have these tools and would freeze during the colder months with water stuck inside their veins. They wouldn’t be able to recover from this, and the tree would die. To get around this, they just grow new leaves each year and store nutrients to survive winter.
The purpose doesn’t stop there.
After they hit the ground, the leaves eventually decompose. This provides the soil underneath with nutrients, which in turn can help the tree, and the plants and animals surrounding it. Not only do leaves on the ground do this, but they also act as a mulch. Insulating the roots from chilling temperatures, the tree is able to maintain a level of moisture and more moderate temperatures.
Beautiful fallen leaves.
Now when your parents ask you to rake the leaves, you can tell them that there are benefits to leaving them on the ground (just make sure to keep storm drains clear)! With this, I hope you enjoy watching trees turn colors and drop their leaves this fall, knowing that they have a method to their madness!
Lani is a Junior at Beaverton High School. As a ZooTeen, she volunteers at the Oregon Zoo during the summer. She plays piano & guitar, and enjoyed doing dragon boats this past year.