- Trails are open 24/7 at no charge. Enjoy a Winnie-the-Pooh themed TRAIL TALES Storybook Walk.
What’s Happening: Clouds
Some generous September rain clouds would brighten our day at Crossroads, but the patchy fog, haze, and days of overcast are not particularly welcome. That is precisely why we chose “Clouds” for our Saturday Science program this week and “Signs of Fall” for next week.
These weekly family programs are geared for kids, but learners of all ages are welcome to the programs, which start promptly at 2:00 pm. The cloud demonstrations—we make clouds with dry ice—are cool and always a big hit with the kids. But adults seem more interested in fall colors. And the two are inextricably related.
Even when we have clouds, the Crossroads solar collectors work, but on bright sunny days the electrical output is much greater. The same goes for photosynthesis. On bright summer days, tree leaves collect the energy of the Sun and convert it to sugars. And on brilliant September days, the leaves make lots of sugars as well. Those sugars activate a pigment called anthocyanin, the one that makes plants red and purple.
Meanwhile, with the shortening days and cooler nights, the movement of sugars into the tree roots slows. At the same time, at the base of each leaf’s stem, a special band of cells called the abscission layer forms. Hormones in the tree trigger this corky layer, which essentially blocks the movement of water and nutrients between the leaf and the rest of the tree. Eventually, the leaves break off at this point.
But on sunny days, until the leaves drop, sugars still build up in the leaves. And the more sugars trapped there are, the redder the leaves—especially on the sunny side of a road or hill.
Fall colors are merely a by-product of deciduous trees shutting down for the winter. But we at Crossroads don’t shut down. Watch our website for a colorful schedule of activities for learners of all ages throughout the fall and winter and beyond.
– by Coggin Heeringa, Interpretive Naturalist
For more information, please check out our Crossroads calendar or stop by the Collins Learning Center and pick up a printed calendar. Our trails are open all day every day, free of charge, thanks to donors like you!
Crossroads at Big Creek Learning Center and Nature Preserve is located at 2041 Michigan Street, Sturgeon Bay. Crossroads is a 501(c)(3) organization committed to inspiring stewardship of the environment through education, research, and outdoor experiences. We welcome your support.
Upcoming Activities
