If April is the cruelest month, then its counterpart in September may be the most hopeful. The cool, morning air is crisp. Late sunrises and long sunsets have greater value. Wildlife begins to scramble toward winter’s approach. And the trees begin painting the landscape with warm, intense colors. Whether running through the woods, raking the yard or driving toward grandma’s house, autumn is my favorite time of year.
Yet, the last time I consider why the leaves change color was second or third grade. What I retained from those lessons is how to spell photosynthesis. So why do leaves change color?
Green feeds trees. The reason our lawns and parks stay green for much of the year is that chlorophyll, which appears as a green hue, is the key driver of photosynthesis. Leaves convert carbon, water and sunlight into the carbohydrates that feed the rest of the tree. Lower temperatures, decreased moisture and most importantly, increased darkness shuts down photosynthesis in the autumn and winter months.
The tree prepares for hibernation by sealing each leaf off from the rest of the tree. Chlorophyll breaks down and with it the green pigment disappears from the leaves. What color remains are the yellow and orange pigments within carotene and xanthophyll. So maybe its wrong to say that leaves change color. It’s just that the green exits and lets the warmer colors thrive.
The brilliant reds that some leaves take on are not completely understood, but many observers note that stressful years with dramatically cold temperature or excessive sunlight contribute to red leaves. The color is anthocyanin and it may be released to protect the tree from sunlight or to extract all the sugar left in dying leaves.
Other theories assert certain colors attract insects that evolved with the tree.
The process if far more complex but the result remains beautiful every year. That is, until the leaves actually fall and pile across my lawn.
Get Ready for falling leaves
All Echo Blowers on Sale!
All Echo Repower Kits on Sale!
Yet, the last time I consider why the leaves change color was second or third grade. What I retained from those lessons is how to spell photosynthesis. So why do leaves change color?
Green feeds trees. The reason our lawns and parks stay green for much of the year is that chlorophyll, which appears as a green hue, is the key driver of photosynthesis. Leaves convert carbon, water and sunlight into the carbohydrates that feed the rest of the tree. Lower temperatures, decreased moisture and most importantly, increased darkness shuts down photosynthesis in the autumn and winter months.
The tree prepares for hibernation by sealing each leaf off from the rest of the tree. Chlorophyll breaks down and with it the green pigment disappears from the leaves. What color remains are the yellow and orange pigments within carotene and xanthophyll. So maybe its wrong to say that leaves change color. It’s just that the green exits and lets the warmer colors thrive.
The brilliant reds that some leaves take on are not completely understood, but many observers note that stressful years with dramatically cold temperature or excessive sunlight contribute to red leaves. The color is anthocyanin and it may be released to protect the tree from sunlight or to extract all the sugar left in dying leaves.
Other theories assert certain colors attract insects that evolved with the tree.
The process if far more complex but the result remains beautiful every year. That is, until the leaves actually fall and pile across my lawn.
Get Ready for falling leaves
All Echo Blowers on Sale!
All Echo Repower Kits on Sale!
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