Some generous September rainclouds would brighten our day at Crossroads, but the patchy fog, haze, and overcast days 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 toward kids, but learners of all ages are welcome. The programs start promptly at 2:00. The cloud demonstrations—we actually make clouds with dry ice—are cool and always a big hit with the kids. But the adults seem more interested in fall colors, and the two are inextricably related.
Even when we have clouds, the Crossroads solar collectors work, but the electrical output is much greater on bright sunny days. 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 also make lots of sugars. Those sugars activate a pigment called anthocyanin, which 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, a special band of cells called the abscission layer forms at the base of each leaf's stem. 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 trapped sugars there are, the redder the leaves—especially on the sunny side of a road or hill.
In reality, 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.
Saturday, September 27
2:00 Saturday Science: Clouds
Geared for elementary students but open to all ages, through indoor and outdoor demonstrations (yes! dry ice involved) and activities, learn about different types of clouds and how they affect the environment. Reservations not required. Free and open to the public. Meet at the Collins Learning Center, Crossroads, 2041 Michigan, Sturgeon Bay.
Monday, September 29
1:30 Video Presentation: “Beauty on the Wing”
Learn why butterflies are essential to the environment. Free and open to all ages. Meet at the Collins Learning Center, Crossroads, 2041 Michigan St., Sturgeon Bay.
Wednesday, October 1
10:00 Junior Nature Club
This program explores nature and includes free play for children ages 3–5 and their adult companions. The topic will be “bridges”—a toddlers’ favorite! No pre-registration is required. Meet at the Collins Learning Center, Crossroads, 2041 Michigan Street, Sturgeon Bay.
1:30 Wandering Wednesday
Join a naturalist on a guided hike through Crossroads's trails. It will be easy walking and last about an hour. No pre-registration is required. Meet at the Collins Learning Center, Crossroads, 2041 Michigan St., Sturgeon Bay.
