Red autumn leaves result from a different process: As the chlorophyll diminishes, a red pigment, anthocyanin, which was not previously present, is produced in the leaf.

These facts were only recently discovered and led to a surge of research studies that attempted to explain why trees expend resources on creating red pigments just as they are about to shed their leaves.

An evolutionary ecology approach infers that the strong autumn colours result from the long evolutionary war between the trees and the insects that use them as hosts.

These results were published in New Phytologist.