Why Leaves Change

The brilliant colors of creation are often biologically helpful, sometimes in more ways than one.  A coral reef’s vibrant palette protects against the sun’s ultraviolet rays, and at the same time helps the coral attract mates.  The bright hues of flowers lure pollinating insects and birds.

So what about the colors of fall foliage?

Turns out that’s a different story.  Many leaves contain yellow and orange pigments all year round, but in the spring and summer they’re masked by the vivid greens of chlorophyll, the pigment responsible for the absorption of light to provide energy for photosynthesis.  But as the days shorten and the temperature falls, the chlorophyll breaks down and drains away - and those yellows and oranges begin to shine through. They were there all along, quiet and unnoticed, but now they emerge as the green curtain fades.  If God is a painter of autumn trees, what we see is an art not of addition but of subtraction. It’s an art of revelation, of revealing the hidden beauty of what was always already there.

But what about those stunning reds?  Those pigments appear when the leftover sugars in certain leaves are transformed into anthocyanins, red and purple pigments.  And that transformation, incidentally, is most intense where there is the most light - which is why the leaves (or even the parts of leaves) most bathed in sunlight are the most deeply red of all.  Ditto for the sunny sides of apples; that’s where the crimsons emerge. As it turns out, the Divine Artist paints not only by revelation, but also by transformation.

So the next time you take a walk or a bike ride through a landscape alive with changing fall foliage, recall that this grand spectacle - arguably one of the most beautiful annual changes in the world - is a sheer riot of glory for glory’s sake. It’s a tide of splendor spilling over the world’s brim, flooding the forest for no biologically advantageous “reason” other than its own radiance.

And recall, too, that those oranges and golds arrive by way of revelation, disclosing what’s been there all along; and those reds and purples, by a transformation of leftovers. A divine sermon in pigment and light, shimmering for all who have eyes to see.

Happy fall, everyone!

Love,
The SALT Team