Why Do Leaves Change Color in the Fall?

Why do leaves change color in the fall? Explore a big maple’s changing leaves and find out what scientists measured. Green chlorophyll breaks down, making yellow and orange pigments easier to see. Many trees produce new red pigments in the fall. For trees like this maple, shorter days are the main signal; weather affects timing and brightness. A special layer helps leaves separate, and dropping leaves helps many trees save water through winter. What you'll see The yard and leaf diagrams are illustrations. The chart summarizes published measurements from a study of four kinds of plants; it is qualitative, with no numbers. The pigment and leaf-separation diagrams are labeled models. The real leaf photo is an observation, not a measurement. The backgrounds and some props were AI-generated using Canva; the otter’s winter scarf was AI-generated using Leonardo. This animated episode uses synthetic narration; no realistic synthetic footage is shown. Photo: “Leaf colors” by frankieleon, via Wikimedia Commons, https://commons.wikimedia.org/wiki/Fi.... Licensed CC BY 2.0: https://creativecommons.org/licenses/.... Cropped in the video. Sources for parents and teachers USDA Forest Service, “Science of Fall Colors” (text checked in the Internet Archive copy dated 2024-12-26; https://web.archive.org/web/202412261...) University of Missouri Extension, “Autumn Colors” (https://extension.missouri.edu/public...) JayDee Gunnell, Utah State University Extension, “What Causes Autumn Leaves to Change Color?” (https://extension.usu.edu/news_sectio...) Illinois Extension, “Marcescence explained” (https://extension.illinois.edu/blogs/...) Illinois Extension, “How plants survive freezing temperatures” (https://extension.illinois.edu/blogs/...) Illinois Extension, “Why do some trees retain leaves over winter?” (https://extension.illinois.edu/blogs/...) Minnesota Extension, “Frozen forests” (https://extension.umn.edu/about/our-s...) Li, Aubrey & Sun (2017), “Predictive capability of a leaf optical meter for determining leaf pigment status during senescence,” Photosynthetica 55, 543–552, abstract (https://ps.ueb.cas.cz/artkey/phs-2017...) For parents and teachers: Which pigments went down in the study, and which stayed about the same? Explore how leaves and seasons change. Guess. Test. Find out!