As summer comes to a close and the temperature outside begins to cool, many of the trees around the United States begin to change colors. The once green leaves begin to transform from green to dazzling shades of red and vibrant yellow. Have you ever wondered why this transformation occurs in the first place? Read below to learn more!
An Unseen Chemical Reaction
During the spring and summer months, a tree’s leaves are responsible for producing the nutrients essential for a tree’s growth through a process known as photosynthesis. As the roots of a tree absorb water and minerals from the soil, and its leaves absorb carbon dioxide from the air, a chemical within the leaves themselves called chlorophyll (which give leaves their green color) combines the two, creating glucose and other compounds that the tree feeds on.
Each fall, many trees and plants stop producing chlorophyll to conserve energy to prepare for the coming winter. Due to this lack of chlorophyll production, other pigments within the leaves themselves begin to show through. These include:
- Xanthophylls – produces variations of yellow
- Carotenoids – produces orange hues
- Anthocyanins – produces shades of red
Because these pigments take longer to break down than chlorophyll, during the warmer months when a tree is continuously undergoing photosynthesis, they remain hidden. In addition, external factors including light, temperature and water also affect a leaf’s coloration. According to the U.S. National Arboretum, cooler temperatures and high levels of sunlight cause the faster deterioration of chlorophyll and cause leaves to change color at a faster rate.
Celebrate Fall with the National Inventors Hall of Fame
While enjoying the brilliant colors of the fall foliage, we invite you to send your pictures of colorful trees to our Camp Invention® Facebook page using #CampInvention. In addition, we encourage you to learn about a few of our world-changing Inductees who have connections to this season of change.
Warren S. Johnson: Inventor of the first multizone automatic temperature control system commercially feasible for widespread application.