I took a weekend trip to Door County recently and as I prepared for the journey, several people commented on how nice they expected “the colors” would be. They were, of course, referring to the fall foliage, and indeed the Fall Color Report from Travel Wisconsin noted Door County would be just before peak color that week. When I arrived, true to the data, the sumacs, maples, and ash trees dotted the landscape with red and gold, while the oaks and hickories were still green.
Each species of tree or shrub changes color at a slightly different time based on its phototrophic needs but in general, as the length of daylight decreases, the photosynthetic process slows and chlorophyll begins to break down. As the green fades, the yellow and orange pigments that were there all along are allowed to shine through.
Carotene pigments (also found in carrots), which absorb orange wavelengths, appear as orange to our eyes, and xanthophyll (found in squashes) create a yellow hue. While these pigments don’t play a starring role in photosynthesis, they do aid in the process by absorbing and using shorter light wavelengths (like ultraviolet) and by dissipating destructive, high-energy forms of oxygen that form during photosynthesis.
Find out more about fall leaf colors from this brief video from Untamed Science, including details on the red anthocyanin pigments that are not there year-round, but develop on bright, sunny fall days.
Did you know…
Chromatography is the separation of plant (and other) pigments. Try this lab experiment to see the differing pigments hidden in a green leaf: Start by cutting or shredding several fresh, green leaves. Place them in a jar and completely cover with rubbing alcohol. Cover the jar, and let it rest for up to 24 hours. Now cut strips of coffee filter paper and place just the tip of the paper in the solution and tape the other end to the top of your jar. The pigments will soak into the paper at differing rates, revealing the bands of color for each existing pigment. Find details from Playdough To Plato.
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News from Nature Net Members
|The Henry Vilas Zoo is having spooktacular celebrations all month long! Check out what on deck throughout October.||Halloween is in full swing at the Madison Children’s Museum! Head on over to experience some fun and festive activities held through the end of the month.||Learn how to cook through Badger Rock’s Facebook Live Cooking Class. Discover new tips and tricks for the kitchen every week!|
More from Nature Net…
|For Families:||For Educators:||Upcoming Events:|
|Keep your kids excited about nature even as the weather becomes colder!||Apply for our Nature Express Grant and help your classroom out with $300!||Check out all of Nature Net Sites’ fall activities coming up!|
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Betsy Parker, Nature Net Director
Karissa Niederkorn, Nature Net Intern