COLUMBUS, OH -- Ohio's woodlands will turn colorful hues of
red, orange, gold, purple and yellow in coming weeks. And with the
annual autumn change comes the question: How exactly does this
"Late September's cool nights and sunny days kick off a series
of chemical reactions within tree leaves that cause Ohio's
spectacular transition from summer to winter," said Bill Schultz,
fall color spokesman with the Ohio Department of Natural Resources
During summer months, a leaf is green thanks to an abundance of
pigments in the chlorophyll family. These green pigments capture
energy from the sun, using it to manufacture simple sugars that
are necessary for the tree's growth. This is the process many of
us know as photosynthesis.
Photosynthesis steadily consumes the leaf's supply of
chlorophylls, which trees replenish at a steady rate through
summer months. But when days grow short and nights are cool, trees
slow their chlorophyll pigment production. As demand outstrips
supply, the leafy green begins to fade. That allows other
pigments, which have been present in the leaf all along, to show
through the fading green. These are the carotenoids, producing
hues of yellow, brown, and orange.
colors, including reds, purples and their blends, are created by
anthocyanin pigments. Unlike the carotenoids, these pigments are
not present in a leaf all year and develop in sap cells by late
According to Schultz, large quantities of sugar are produced in
leaves during ideal weather conditions. When complemented by cool
nights, the leaf's veins begin to close, preventing the sugars
from being released. These conditions stimulate the production of
the red and purple anthocyanin pigments, particularly in
sugar-rich tree varieties such as maple, oak, sweetgum, dogwood
and blackgum. When high levels of both anthocyanin and carotenoid
pigments are present, leaves display the deeper oranges, fiery
reds and bronzes that can light up a fall landscape.
Trees now cover more than 30 percent of the Ohio landscape - up
from only 12 percent in 1900. Much of that forest cover is
concentrated in the eastern and southern third of the state and
provides spectacular accents to the area's naturally hilly
terrain. Ohio's spectacular palette of fall color stems directly
from the wide variety of tree species in the state. Many are on
the edges of their ranges, making for a breathtaking blend of
golds, oranges, greens and reds.
Ohioans and out-of-state visitors who enjoy viewing the state's
fall color in a variety of locations can call the 1-800-BUCKEYE
tourist information line for the latest forecast information.
Internet users can find the forecast at ohiodnr.com, which also
provides an opportunity to view the weekly change of seasons.
The web site also gives a list of events in state parks and
nature preserves, suggested fall color driving, biking and hiking
routes and top opportunities to photograph Fall Color.