Colors for Defense

2001/07/10 Elhuyar Zientzia

• Botanika
• Ekologia

When autumn comes and the days begin to shorten, the trees are filled with colors. Then we see red, yellow and purple with more intensity. The leaves of the trees lose the chlorophyll and the hidden colors are displayed until then. In addition to chlorophyll, the leaves contain other compounds for the photosynthesis process. These compounds are usually red, yellow or orange, but while the leaf is healthy we cannot see them because the chlorophyll green predominates. They only appear in autumn when the leaves approach the end of life.

But for biologists Sam Brown and William Hamilton of Oxford University, color change means something else. They believe that bright colors are indicators of tree health, a strategy to ward off plant lice. Vivid colors encourage plant lice to winter and choose other trees more vulnerable to reproduction. The same very common strategy in the world of insects. See article Color games, if not.