By Charlie Frisk
Correspondent
Wisconsin is about to enter what I consider the most beautiful season, the time of peak fall colors.
We are blessed with red and sugar maples and many species of oaks which put on a spectacular show.
We always talk about the leaves changing colors, but most of the colors we see in fall were there all along.
They were just blocked by the more intense green of the chlorophyll, the pigment responsible for photosynthesis.
Chlorophyll is contained in cellular structures called chloroplasts, where the sugars are manufactured by the leaves.
Throughout the spring and summer, chlorophyll prevents other pigments from being visible.
In fall, as the days shorten, the chlorophyll disintegrates, and the other pigments get their chance to shine.
The yellow comes from xanthophylls, the orange from beta-carotenes.
Xanthophylls function as accessory light-harvesting pigments, and protect the chloroplasts from the potentially toxic effects of light.
Beta-carotene absorbs some of the wavelengths of light missed by chlorophyll.
It also plays a role in protecting the chloroplasts by absorbing excess light during intense sunlight and releasing the light energy as heat.
The red pigments, the anthocyanins, were not there all along; they are produced when about half of the leaf’s chlorophyll has degraded.
Its function is to protect the leaf from excessive sunlight, so the sugars the leaf produced can be absorbed into the trunk and then down into the roots to be stored through winter.
Sugar maples can vary from bright red to yellow.
Sugar maples on the outside of a forest plot will typically turn quite red because those trees are exposed to intense sunlight, and the leaves need more anthocyanins for protection.
Sugar maples found in the interior of a forest plot are yellow because they aren’t exposed to as much sunlight.
Some years have much better colors than others.
Cooler weather and sunny days produce the most vibrant colors.
Whereas warm, rainy and windy weather result in a less colorful and shorter season.
Rain leaches the pigments out of the leaves more rapidly, and high winds blow the already poorly attached leaves off the trees.
Now that we discussed the chemistry, we can get to the best places in Northeast Wisconsin to see spectacular colors.
As president of the Baird Creek Preservation Foundation I’m biased, but I don’t believe there is any place in Green Bay that puts on a show to compare with the Baird Creek Greenway.
Baird Creek has many maples and red and white oaks, all of which provide good colors.
The best place to see fall colors is to go to Christa McAuliffe Park and take the brown trail.
During the peak of sugar maple colors, there is one section of trail that makes you feel as though you are walking through mythical streets of gold.
It will be golden at your feet, your sides and above your head, a truly breathtaking sight.
Other great locations in the area include several Brown County parks; Pamperin Park, Reforestation Camp, Barkhausen, Neshota Park, Fonferek’s Glen and Lily Lake.
There are also many Green Bay city parks that put on a superb color show, the largest of which is Bay Beach Wildlife Sanctuary.
The Travel Wisconsin website has a fall color map that gives predictions on peak color dates for the entire state.
It predicts the third week of October for top colors in the Green Bay area, but most prognosticators are predicting about a week earlier than that.
In areas where the trees are under stress they will peak earlier.
In bogs, the soils are oxygen- and nutrient-poor so the trees will turn much sooner.
I was at Lily Lake County Park Sept. 18 and the trees in a boggy area on the east shore were already pretty spectacular.
There are many great places in the area to view the fall color show.
This most beautiful season goes fast, so get outside and enjoy it while you can.
Editor’s note: To read another of Charlie Frisk’s Bay Area Blooms, click here.