DID
YOU GUESS IT??
Fall
Colors in Nebraska
Why
do leaves turn colors?
Autumn leaf colors are the result of a chemical change in
the leaves. The trigger is the onset of cooler temperatures
and reduction in day length.
During
the growing season, green leaves are green because of the
large amounts of chlorophyll they contain. Chlorophyll is
the key component in photosynthesis, the process by which
leaves use sunlight and carbon dioxide to make the sugars
and starches the tree uses for food.
As
long as they are growing, trees continually replenish their
leaves' supply of chlorophyll. As the days get shorter and
cooler, however, growth slows and the tree produces less chlorophyll.
As chlorophyll in the leaves breaks down, it isn't replaced,
and the other pigments that have been there all along, masked
by the green, become apparent.
The
intensity of color varies from year to year, depending on
the weather. The conditions most favorable for brilliant reds
are bright, sunny, warm days and cool nights. The leaves produce
more sugar on warm days, and night temperatures below 45 degrees
keep those sugars in the leaves. Pigments are formed in those
sugars, so the more sugars, the more color.
For
more information, read Why
Do Leaves Turn Colors in the Fall? by Don Janssen, Extension
Educator, University of Nebraska-Lincoln Extension in Lancaster
County