Appreciating Autumn

I love how autumn leaves get such a grand "last hurrah" before they fall off the trees. It's a riot of color around here right now. Even mundane chores like sweeping off the steps or going to the mailbox seem like little celebrations. And as much as the kids enjoy the leaves and "ooh" and "ahh" at the pops of color, today I got to wondering if they knew why leaves change color. So I asked them.

"Leaves change color because they get bored of being green," said Charlotte, age 5.

"No, it's because the weather gets colder and colder," said Zachary, age 8."

"But why would the weather affect the leaves?" I asked him.

"The leaves have a certain gene that makes them change color as it gets colder."

Close, but no cigar. Truth be told, I was a little fuzzy on the exact details myself, vaguely remembering something about photosynthesis from science classes eons ago. I decided that a trip to the library was in order.

We found two good books that explained the process of photosynthesis in kid-friendly terms, and funnily enough, they have the exact same title: Why Do Leaves Change Color? The first book is by Betsy Maestro, illustrated by Loretta Krupinski (Harper Collins Publishers, 1994). It's in very simple language, so my kindergartener understood it. The second book, more advanced and right on target for my third grader, is by Terry Allan Hicks (Marshall Cavendish Benchmark, 2011). Both books also give directions for the same project: Preserving leaves by ironing them on very low heat, between two pieces of waxed paper. Betsy Maestro's book also gave directions for making leaf rubbings with crayons--not that it really needs directions, but I appreciated the reminder. I'd forgotten all about how much fun that used to be when I was a kid, and my children enjoyed creating leaf rubbings just as much.

Both books explain that as the weather gets colder and the daylight hours get shorter, the tree begins to prepare for its winter rest and the natural green pigment in the leaves, called chlorophyll, slows its production inside of the leaves. That gives the other pigments (red, yellow, gold, orange, brown and--supposedly--purple) a chance to emerge. In warmer seasons, chlorophyll takes in the sunlight and converts it to fuel (glucose) for the tree to thrive (that's the process of photosynthesis). In colder seasons, the tree doesn't need the extra fuel. Photosynthesis slows down, causing the leaves to dry up and fall off the tree.

As Hicks points out, "The leaves of a deciduous tree fall because they are too delicate to survive harsh winter conditions." Boy, do we ever know it! Last October, a massive blizzard blanketed our area in 18 inches of snow (did I mention it was October?). The poor trees, still thick with leaves, were heavily weighed down by the snow and many didn't survive the storm.

We had no power for four days, and for many weeks afterward our town was buzzing with chainsaws and stump grinders, taking away all of the fallen trees--hundreds upon hundreds of them. (Sigh.) I'm hoping this October, there are no such surprises, and autumn takes its sweet time to unfold. After all, there's a lot more fall fun to be had before the snow arrives.

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