During our last hike we all admired wide range of the autumn colors and I’ve learned from my eight-year
old daughter that all these years I was wrong thinking that the true leaves color
is green.
That’s what she’s learned at the science lab:
“Trees begin to show their true colors in
autumn.”
Here’s
why.
“The
four primary pigments that produce color within a leaf are:
chlorophyll
(green);
xanthophylls
(yellow);
carotenoids
(orange);
and
anthocyanins (reds and purples).
During
the warmer growing seasons, leaves produce chlorophyll to help plants create
energy from light. The green pigment becomes dominant and covers the other
pigments.
Trees
must replenish the chlorophyll because sunlight causes it to fade over time. As
days get shorter and nights become longer, trees prepare for winter and the
next growing season by blocking off flow to and from a leaf’s stem. This
process stops green chlorophyll from being replenished and causes the leaf’s
green color to fade.
The
fading green allows a leaf’s true colors to emerge, producing the dazzling
array of orange, yellow, red and purple pigments we refer to as fall foliage.”
painting by Urszula Glogowska
