The Changing Trees of Autumn

1. The Changing Trees of Autumn By Meryl Spierenburg ED 205 (15) Concept Map About the Author Quit Resources Quit

2. Let’s Learn About the Leaves! • Where do the colors come from? • Why do the leaves change color? • How does it work? • Why do leaves FALL? • What happens after the leaves fall? • How do we get the best colors? Quit

3. Where do the colors come from? • Leaves have pigments that give them their color. • There are 3 pigments are involved in the autumn color. • Chlorophyll • Carotenoids • Anthocyanins How do they all work together? Quit

4. Chlorophyll • Chlorophyll is the pigment that gives leaves their basic green color. • Chlorophyll is necessary for photosynthesis, the chemical reaction that lets plants use sunlight to make food. Quit

5. Carotenoids • Carotenoids are the pigments that produce yellow, orange, and brown colors in the leaves. • The are also found in things like corn, carrots, and bananas. Quit

6. How do they all work together? • Chlorophyll and carotenoid are in leaf cells all the time during the growing season. But the chlorophyll covers the carotenoid . That's why summer leaves are green, not yellow. • Most anthocyanins are produced only in autumn. Not all trees can make anthocyanins. Quit

7. Anthocyanins • Anthocyanins are the pigments that give leaves their red color. • The are also found in cranberries, red apples, blueberries, cherries, and plums. Quit

8. Why do the leaves change color? • Leaves change color mainly because of the longer, cooler nights that occur in Autumn. • As the nights get cooler and longer, a biochemical process takes place that causes the leaves to change in color. • Click here to watch a video about why leaves change color Quit

9. How does it work? • During the spring and summer, chlorophyll is continually being made, and leaves are green. • As the nights get longer in the fall, chlorophyll making slows down and then stops and eventually all the chlorophyll is gone. • The carotenoids and anthocyanins that are in the leaf are then able to show their colors. Quit

10. Why do the leaves fall? • In early autumn, the veins that carry fluids into and out of the leaf gradually close off. • These closed veins trap sugars in the leaf and start the making of anthocyanins. • When this is complete, the leaf is ready to fall Quit

11. What happens after the leaves fall? • On the ground, fallen leaves are broken down by bacteria, fungi, earthworms, and other organisms. • The broken-down leaves give the soil nutrients and become part of the layer on the forest floor that absorb and hold rainfall. Quit

12. When do we get the best color? • The autumn colors are the most vibrant when there has been: • A warm and wet spring • A summer that isn’t too hot or dry • A fall full of warm days and cool nights. Quit

13. About the author This powerpoint was created by Meryl Spierenburg. I am a Junior at Grand Valley State University, majoring in English with a minor in Elementary Education. Please, feel free to e-mail me at: meryljoy@charter.net Quit

14. Concept Map Quit

15. Resources • http://www.jimpetrozzi.com/site_WW/thumb-wallpaper/Red%20Leaves.jpg • http://www.desktoprating.com/wallpapers/nature-wallpapers-pictures/fall-of-autumn-leaves-wallpaper.jpg • http://www.jimpetrozzi.com/site_WW/thumb-wallpaper/Red%20Leaves.jpg • http://riversaredamp.files.wordpress.com/2007/10/yellow-leaves.jpg • http://www.pewclimate.org/docUploads/images/green%20leaves%20with%20rain%20drops.jpg • http://www.dnr.state.wi.us/org/caer/ce/eek/veg/trees/treestruecolor.htm • http://www.na.fs.fed.us/spfo/pubs/misc/leaves/leaves.htm • http://www.esf.edu/pubprog/brochure/leaves/leaves.htm • http://farm1.static.flickr.com/113/315997493_35bc95c19c_o.jpg Quit