PREVIOUSLY: « Grabbing the long tail of search engines  Climate change hot air »

Nov 4, 2006

Why do leaves turn red in autumn

Posted in Chemistry at 1:00 am by David Bradley -- 2 Comments; add your comment

red-leavesWhy do leaves turn red in the fall? It’s all down to chemistry. Red pigments known as anthocyanins form in leaves from many plant and tree species at the same time as the green photosynthetic apparatus is dismantled by the plant during which nutrients containing nitrogen (N) and phosphorus (P) are re-absorbed by the plant from its leaves for winter storage. If these nutrients are not resorbed next year’s growth is inhibited. As the levels of green compounds in the leaf falls and anthocyanins rise so the leaves of many species change from verdant to rusty with a range of colours in between.

For more information on why leaves turn red in autumn, check out this page from Wisconsin U

Newsfeed

2 Comments »

  1. john smith said,

    November 5, 2006 at 12:37 am

    i think you should consider the importance of a freeze in early autumn. without this many maple leaves go from green to yellow and fall without ever going red.


  2. sciencebase said,

    November 6, 2006 at 9:30 am

    Good point John, there are several species that never really produce red leaves, perhaps I should expand on this post to explain the glut of compounds produced in various species that give rise to the whole gamut of autumnal colours.


Comments: What are your thoughts on this? Leave a comment

You can use <b>, <i> and add a link or two using <a href="">. All comments are checked for spam before they appear.

Related Science Articles: