ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Why Do Leaves Change Color in Fall?

Updated on September 17, 2017
Colorful Autumn Leaves
Colorful Autumn Leaves | Source

Autumn is the time of year Mother Nature dazzles us with her display of colors. Take a drive through the countryside or a walk through a park, and you'll be treated to various shades of red, gold, orange, and even purple. Have you ever wondered why this happens every year?

To truly understand what's going on, we need to talk about the science of the leaf (don't worry, I'll try to keep it simple).

The Leaf's Purpose

Leaves are very beneficial for us and many other animals. They help a tree provide shade, and even more importantly, oxygen exits the plant through the leaves' pores. However, the main purpose of the leaf is to help the tree produce its food through photosynthesis. Photosynthesis is an extremely complex chemical process, but to boil it down, it's the process a plant uses to harness energy from the sun to create sugar from carbon dioxide and water.

Chloroplasts from a leaf, as seen through a microscope.
Chloroplasts from a leaf, as seen through a microscope. | Source

Plastids and Plant Pigments

You may recall from school that cells have structures called organelles, which all have specific functions. Plant cells have organelles called plastids, which manufacture and store compounds. Some types of plastid - chloroplasts and chromoplasts - contain pigments. Chloroplasts are where photosynthesis takes place, and it happens with the help of chlorophyll, a green pigment. (There are actually different types of chlorophyll, but in the interests of keeping things relatively simple, I'm throwing them all together here). Chromoplasts are responsible for synthesis and storage of carotene and xanthophylls, as well as other pigments. You probably already know of some foods that are rich in carotene, such as carrots and sweet potatoes, so it probably doesn't surprise you that carotene is orange/yellow in color. Xanthopylls are also yellow. Anthocyanins can be red, purple, or blue, and are found in the cell vacuoles. Blueberries, blackberries, and cherries are rich in anthocyanins.

From Green to Red, Orange, Yellow, or Purple

In spring and summer, leaves are continuously making chlorophyll, which is what gives them their green color. As we know, there is less sunlight and temperatures start cooling down once autumn arrives. The reduced light tells the tree that it's time to start getting ready for winter, and the tree then shuts down production of chlorophyll by sealing off the flow of water to the leaf. The chlorophyll that is already in the leaf's cells breaks down, and the other colors that are already in the leaf are now able to show through. The color varies by species of tree.

The weather also has some influence when it comes to reds and purples. Warm days with plenty of sunshine and cool nights is the best combination. The sun and warmth stimulates production of sugar, and the cool nights signal the veins to close off. This keeps the sugar in the leaf. This also causes more anthocyanins to be produced, which leads to more brilliant reds.

Why do trees go through this? Leaf tissue freezes easily, so trees must shed leaves before winter as a way to protect themselves from damage. Of course, this does not apply to evergreen trees, which have leaves (needles) that are much tougher, and are able to survive cold temperatures.

Comments

    0 of 8192 characters used
    Post Comment
    • jenb0128 profile imageAUTHOR

      Jennifer Bridges 

      7 years ago from Michigan

      Thank you, thank you!

    • aviannovice profile image

      Deb Hirt 

      7 years ago from Stillwater, OK

      Good information, Jen, that was broken down into understandable terms.

    • kashmir56 profile image

      Thomas Silvia 

      7 years ago from Massachusetts

      Great hub and very informative on why the leaves change color at autumn time . Well done !

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://maven.io/company/pages/privacy

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)
    ClickscoThis is a data management platform studying reader behavior (Privacy Policy)