Monday, October 01, 2007

The Rake's Progress

The leaves are just beginning to turn and the needle fall for the white pine has covered the ground beneath it with a soft brown carpet. That means it is time for my yearly contemplation of modern man's failure to comprehend the simplest of things.

Yearly, in this case, does not mean that it is an annual event; it means rather that it starts a new year long musing session.

By the end of October, my suburban neighbors will be hard at work ensuring that the, to them, ugly brown detritus of the trees is raked up neatly and bagged. The bags will be stacked at the curb for the town to pick up and haul to the dump. Every year I ponder this folly before, browbeaten by my wife, I succumb and do the same.

But it always bothers me.

It's not that I mind the work. It's that I don't understand why it should be done other than as a sop to the others who live on our street.

My reasoning is simple. Nature is full of elegant design. Sometimes that design is quirky, but nonetheless it has a meaning of its own. I could talk about Darwin, or D'arcy Thompson's wonderful book "On Growth and Form" or any of the several volumes by Stephen Jay Gould such as "The Flamingo's Smile" or "The Panda's Thumb", but I will not. Instead, I will just talk about the design in my own yard.

I look at the maple tree next my my driveway. Its leaves have not yet turned but they will. As the days get shorter, the chloropyll will gradually leach out of the leaves, taking the green color with it. Red will start to become the predominant color. (The leaf is not actually changing color, the red has been there since it emerged in spring. In fact, the reason the tree is called a "red maple" is because when the leaves first appear and before the chlorophyll starts working they are red.) Their hold on the twigs, so firm throughout the Spring and Summer becomes tenuous and they start to fall off.

But why do they fall? Why do deciduous trees drop their leaves for the cold season? Wouldn't it conserve energy for the tree to retain the leaves and re-activate them in the spring?

Well certainly one reason is to reduce the weight of the potential snowfall on their branches. Unlike the more flexible evergreens, maples are hardwood. Their branches are more brittle. They also grow more slowly than their softwood brethren. Dropping leaves is a way to minimize the surface on which the snow's weight will rest.

Nature isn't simplistic. Evergreens will drop some of their needles, too. That's because there are two more reasons for the leaves to fall.

One of these is the protection of the roots. Although the leaves may scatter, the vast majority of them stay where they fall blanketing the roots of the tree ... and I use the term blanket on purpose. The leaves will insulate the roots from the frost and ice to come. Like an electric blanket, they even will provide additional warmth as the wet leaves decompose and the mulch turns into compost.

And that's the last main point. The decomposition of the leaves not only warms the roots, but returns the nutrients that the tree needs back to the soil, ready to be picked back up as the sap rises in the Spring.

It is a cycle that is truly elegant. A full circle of life and death efficiently letting the tree nurture itsself.

Who was it that persuaded us that interrupting this process was right? How have we managed to persuade ourselves that dead leaves are eyesores and serve no purpose but to create an opportunity for mild exercise?

It is a puzzlement.

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