This is the time of year when Nicole Hughes gets constantly distracted by the fall foliage as she drives around North Carolina. "I'm always looking," says Hughes, a biologist at High Point University.

Behind every autumn leaf lies a chemical shift-chlorophyll fading, carotenoids glowing, anthocyanins rising-that turns survival into spectacle. Every autumn, landscapes across much of the world ...

The autumn leaves could show up late this year — and with softer shades. Why it matters: Fall foliage isn't just pretty scenery or a tourism draw — its timing and vibrancy could flag deeper forest ...