Autumn arrives in late September, but it doesn’t take long for a kaleidoscope of brilliant yellows, robust oranges and fiery reds to adorn the October landscape. Cooler temperatures, a reduction in daylight and increased amounts of sugar in leaves trigger a variety of chemical changes involving carotenoid, flavonoid and anthocyanin compounds. Our eyes bear witness to what we see, but vision can't reveal what our nose instinctively knows—that autumn has a smell.
The presence and degradation of color-inducing chemical compounds mingle with changes in temperature. The air is crisper than it was in summer and smells are less varied and more distinct. Dry pine needles cushion footsteps on forest paths, releasing a vanillic, woody pine-like odor as twigs and sticks crackle underfoot. The aroma of wet autumn leaves pours over the senses like honeyed amber treacle. Humus, the decomposition of leaves by soil bacteria that will nurture plants in the spring, adds earthiness to the fragrant mélange.
There isn’t a word for the smell of autumn. Perhaps it’s because several aromatic shifts take place before winter arrives, each with it’s own distinct set of smells. The incense of chimney smoke redolent with shadows of tree sap and resin will soon replace these scents. Warm spices will trill our tongues and the slow evaporation of complex perfumes will ease the longing for new plant life to emerge. Many will eat the bright and brindled colors of autumn at the winter dinner table, and dream of long sunsets. It won’t be long before new smells surface in the landscape and another kind of restlessness overtakes the senses.
