By Charlie Frisk
Fall is my favorite time of the year — I love the cooler temperatures, the fresh feeling in the air, watching migrations of birds, butterflies and dragonflies.
But what I enjoy the most are the spectacular fall colors.
Wisconsin is blessed with a variety of trees that provide great colors – red and sugar maples, all of the oaks and even some of the conifers such as tamaracks.
One of my daughters lives out west, and they get yellows but almost none of the oranges and reds that we are so fortunate to see here.
We always talk about the leaves changing colors, but most of the colors we see in the fall were there all along, they were just being blocked out by the more intense green of the chlorophyll.
A little bit of science
Chlorophyll, the pigment responsible for photosynthesis, is contained in cellular structures called chloroplasts, where sugars are manufactured by the leaves.
Throughout the spring and summer growing season, chlorophyll prevents the other pigments from being visible.
In fall, as the days shorten, the chlorophyll disintegrates and the other pigments get their chance to shine.
The yellows we see come from xanthophylls, while the oranges come from beta-carotenes.
The xanthophylls function as accessory light-harvesting pigments, and they protect the chloroplasts from the potentially toxic effects of too much light.
Beta-carotene absorbs some of the wavelengths of light missed by chlorophyll.
It also plays a role in protecting the chloroplasts, both by absorbing excess light during intense sunlight periods to later be released as heat, and by mopping up energetic oxygen molecules that could damage other cell structures.
The red pigments – the anthocyanins – were not there all along.
They were produced when about half of the leaf’s chlorophyll had been degraded.
Their function is to protect the leaf from excessive sunlight, so the sugars the leaf produce can be absorbed into the trunk and then down into the roots to be stored through the winter.
Sugar maples can vary from bright red to yellow depending on location.
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.
Evergreens add to the show
Although most conifers don’t lose all of their needles, they do undergo changes in preparation for the freezing months.
Botanists refer to the changes they make as “hardening off.”
During this period, conifers largely cease photosynthesis, and many species such as white cedar will drop up to a fourth of their needles.
One of the concerns that botanists have with climate change is that with warmer and wetter fall season conifers will delay hardening off, which will lead to more winter kill.
The tamarack, also known as larch, is a deciduous conifer.
Deciduous is Latin for fall off or fall down.
Tamaracks lose all of their needles, but first the needles turn a beautiful color which Aldo Leopold referred to as “smoky gold.”
Some years have much better colors than others.
Cooler weather and sunny days produce the most vibrant colors, whereas warm, rainy and windy weather results in a less colorful and shorter season.
Rain leaches the pigments out of the leaves more rapidly, and high winds take the already poorly-attached leaves off of the trees.
Now the fun part
Now that we’ve discussed the chemistry of color change, we can get to the part that really interests most people, the best places in Northeast Wisconsin to see those spectacular colors.
As President of the Baird Creek Preservation Foundation (BCPF), I am obviously biased, but I don’t believe there is any place in Green Bay that puts on a color show to compare with the Baird Creek Greenway.
Baird Creek has many sugar and red maples and red and white oaks, all of which are species that provide good colors.
The BCPF recently installed trail maps at most trailheads and a trail-marking system.
The best place to see fall colors is to go to Christa McAuliffe Park and take the Brown trail.
During the peak of the 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 Green Bay area include Pamperin Park, the Reforestation Camp, Barkhausen, Neshota Park, Fonferek’s Glen and Lily Lake.
For more information and directions for these Brown Co. Parks and others go to the Brown County Parks website.
There are also many Green Bay city parks that put on a superb color show, the largest of which is Bay Beach Wildlife Sanctuary.
To find these parks, go to the Green Bay Parks, Recreation and Forestry website.
The Travel Wisconsin Website has a fall color map that gives predictions on peak color dates for the entire state.They are predicting the third week of October for top colors in the Green Bay area, but colors should be good by the next week.
By the time you read this, much of the northern portions of the state will be past their peak.
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.
Lily Lake County Park is a great place to get a jump on the color show because much of the shoreline is boggy.
There are many great places in the Green Bay area to view the fall color show.
This most beautiful season goes fast, so get outside and enjoy it while you can.