October 2005

17 October 2005

As if by flick of a switch, fall has arrived on campus.

The trees, those not evergreen, have switched off the cellular factories that have been working dawn to dusk all summer. Chlorophyll, the dominant light absorbing pigment, now no longer needed, is breaking down and moving out of the leaves. Left behind, carotene and xanthophylls are revealed by the absence of green and our campus comes alive in yellow and orange.

These cellular changes mark the end of a season. Sealing the doors of the abandoned factories, the trees cut off their connections to the stem. With the next gust of wind, the leaf drifts down. For the leaf, the light is out. But like so much in nature the end of one is the beginning of another. Under the newly fallen leaf, in soil freshly moistened, the spore of a mushroom awakes. Feasting on the carbon gifted by the tree, the fungus builds its soft self. Unnoticed and unremarkable, the fungus performs its vital function-- returning sequestered nutrients to the earth thereby insuring their use by another generation of sun catchers.

The light may be out for the leaves, but their glow brightens our campus for at least a few days before the wind moves them on to their next role in the ongoing play that is life on earth.

with an eye on nature,

Wally