While we were examining the effects our screwy winter/spring weather was having on our trees this year, it reminded me of a cool idea I had many moons ago.
My school was in an area of Arvada they were redeveloping. That meant trees that had been there for probably more than 100 years were being cut down to make way for progress. I love trees, and in a high desert clime, I’ve always hated seeing old trees come down. Anyway, they were in process of cutting down a huge old cottonwood tree when the idea hit me.
As a sixth grade teacher, we were responsible for teaching ecosystems, as part of our Outdoor Lab curriculum. A cross-section, 2-4” thick would make an awesome teaching tool to support this unit. We could use a clear-coat sealer to preserve the wood, adding legs to make it a table. But the real use of this four to five foot diameter disk would be a multi-purpose learning tool. It would be our own “giving tree”. (Actually, I think it was bigger, but didn't want to turn this into another "fish" story.)
We’d start with the science behind the tree itself. How does it grow? What do the different layers represent? What is its part in the photosynthesis process? What does a tree need to survive? How does it get nutrients? How does that compare to other living things?
Counting the rings would give us an approximation of its age, but I wanted to take that further. The thickness of the rings would tell us when the dry years occurred, compared to the thicker, and consequently wetter years. Using that information, we could correlate with old weather records, double-checking our suppositions. What were the major weather events that could have affected our tree?
Our math connection was to include the circumference of the trunk, as well as the radius and diameter of our friend. (By this time, I’m sure we would have named him.) What was the measurement of the thickest ring? What about the thinnest ring? We could graph our data, comparing it to our weather history.
Next, who says timelines have to be linear? I saw us labeling the decades as we made our way in the concentric circles to the center of the tree. From that point, our tree became an historical timeline of events happening in our city, our state, our country, the world during those periods. How big was the tree when my current class of students were born?
The guys cutting the tree down were willing to cut a slab and my teammate loved the idea, right up until we realized we had no room for it and it was too heavy to move. It took awhile for me to let go of the idea and was really sad to see it chopped up for someone’s firewood.
As I said, this was many moons ago, before we had the internet and computers in the classroom. Now, there are great resources from NOAA’s National Climatic Data Center, as well as many more ideas and lessons, just a click away. Kind of takes some of the romance out of it, don’t you think?
Anyway, if anyone sees a large old tree being cut down, and you have the space, consider making your own “giving tree”. Then let me know how it worked for you.
"When one tugs at a single thing in nature, he finds it attached to the rest of the world." John Muir