Trees and their «colour factory»

From late summer onwards, forests are so brightly coloured because the trees take a break in winter and go into hibernation. When the days grow shorter and the nights cooler, the trees draw valuable chlorophyll from their leaves and pass it down to their roots. Chlorophyll is important to plants. They use it to capture the sunlight they need in order to grow.

When the tree sends chlorophyll to its roots from late summer on, it is storing a source of energy that it can «tap» in the spring in order to grow leaves again. During the summer, the green leaf pigment chlorophyll conceals other pigments. When the chlorophyll gradually disappears in the Indian Summer, yellow to red carotenoids and yellow xanthophylls come into their own, creating the autumn colours.

The intensity of these colours may depend on the temperature. If the nights turn cold early in the autumn, the chlorophyll is carried away quickly and only the glowing colours are to be seen. So now you know!