Family outings at Crossroads are special. When youngsters are along, it takes a little extra time to cover a trail, but we always survive and usually notice things that otherwise might have escaped us. Along the trails, kids ask the most interesting questions like, for example, why do some trees stay green in the winter?
Deciduous trees can make food very fast and efficiently and that is a good thing. Tree leaves usually have only five months between the time they open in spring until they fall in fall. Evergreen trees are not as efficient at making food, but these trees are able to survive because they have a little extra time.
Because pine, spruce, and fir trees stay green in winter, their needles have more time for photosynthesis….to take the energy of the sun and make it into food. And that, I believe, is the real reason evergreens stay green in winter.
Certainly, there are evergreen trees all over the world in almost every climate, but the species we think of as Christmas trees usually grow in places that have long, cold winters or that have extremely poor soil. In spring, when deciduous trees are still waiting for their leaves to open, evergreen trees are making food and new wood.
If broadleaf trees kept their leaves all year, snow would seriously damage them. I remember one year, we had a heavy snowfall while leaves were still on the trees. I was awaken during the night by the din of crashing branches and whole trees being uprooted.
That usually doesn’t happen to pines and spruce. They are tapered and their branches are flexible. After a snowfall, especially a heavy, wet snowfall, the branches of evergreen trees tilt at about the same angle as a playground slide. When snow slips off the needles, it slides down, just like a kid on at the playground. Very heavy snow makes branches dip, causing tiny avalanches.
A wax coating on the needles helps snow slide off. At the same time, the wax prevents the tree from drying out. Sometimes when the wind blows and ice crystals are in the air, the wax gets stripped from the needles. Without the wax coating, the needles dry out, turning brown and ugly.
Another thing prevents dehydration in an evergreen is that the needles are slender. Unlike deciduous tree leaves, needles do not have a large surface area from which water can evaporate.
Researchers are continually discovering more about evergreen adaptations. They found out that evergreen needles can get water out of fog and low clouds. Even more amazing, the needles seem to be able to filter minerals right out of the air.
We still have a lot to learn about how evergreens survive winter, but we do know that staying green in winter gives them a little extra time to grow in the spring. And green certainly makes them beautiful for the holiday season.
Saturday afternoon at 3:00, Crossroads will host a Family Hike to the Evergreen Forest starting from the Collins Learning Center. If their are little ones along, we will take a little extra time, but we will be back by dark.
Crossroads at Big Creek is a learning center made up of The Cove, Big Creek and Ida Bay preserves. Trails are always open. The Collins Learning Center, located at 2041 Michigan, is open 2:00-4:00 daily and during scheduled events.
Thursday, December 7
6:30 Volunteer Training for Ski for Free Program
Hands-on training will be provided to prepare volunteers (and prospective volunteers) for outfitting visitors with cross country skis and snowshoes for use on Crossroads’ groomed trail system. Volunteer commitment time is flexible. Ski for Free is sponsored by Friends of Crossroads and Door County Silent Sports and will begin once we have adequate snow. Meet at the Collins Learning Center.
2:00 Friday Film: Chasing Ice
Thanks to the Climate Change Coalition of Door County, we have screening rights for this stunning film which documents the acclaimed environmental photographer James Balog’s assignment for the National Geographic: to travel to the Arctic to capture images to help tell the story of the Earth’s changing climate. This presentation is free and open to the public. Meet in the lecture hall of the Collins Learning Center.
Saturday, December 9
3:00 Family Hike to the Evergreen Forest
Hikers of all ages are welcome on this gentle ramble to several of the evergreen forests of the Big Creek Preserve. If youngsters are along, we will take “a little extra time”, but will be back before dark. Free and open to the public. Meet at the Collins Learning Center.