Why Autumn Leaves Turn Red
October 30, 2007
From Nature News
Autumn leaves turn fiery-red in an attempt to store up as much goodness as possible from leaves and soil before a tree settles down for the winter.
The worse the quality of soil, the more effort a tree will put in to recovering nutrients from its leaves, and the redder they get.
That's the conclusion that Emily Habinck from the University of North Carolina, Charlotte, came to after looking at trees in a flood plain and in an adjacent upland area. The soil in the upland area was low in nutrients, and the leaves there were bright red. In the floodplain, where the soil was packed full of goodness, the autumn leaves remained yellow.
"In a nutshell: the redder a leaf is, the more nutrients it is going to recycle," explains Habinck, who presents her findings at the Geological Society of America's annual meeting in Denver, Colorado, today.
The full article is available at http://www.nature.com/news/2007/071029/full/news.2007.202.html.