The mixed forests in the steigerwald and the habbergen are currently offering a magnificent play of colors. Green, yellow, ocher, orange, red, brown: the treetops shine in many colors, they outshine the landscape everywhere. The eyes of the observer are pleased. The biologist is sorry. Not really, it was just because of the rhyme: the biologist answers the question why all the colors are like this. But he first has to make a long story short.
Limited water available
It is clear what follows after the colorful show. Most deciduous trees shed their leaves. Jurgen thein, biologist and nature paddagoge from habfurt, can explain it all in context. "First of all you have to ask yourself: why do they shed their leaves??", it begins. Most people know the answer from school: in winter, trees have only limited water available to them. When the ground freezes, they may have to survive days or weeks of drought. If they had (active) leaves in the geast in such a phase, they would not grab it. "They lose a lot of water through the leaves", explains thein.
No wonder, because the flatness of the leaves makes up a large part of the tree. A deciduous tree growing in these latitudes carries an average of 30,000 leaves. The older and coarser it gets, the more there are. When it is between 80 and 100 years old and 25 to 30 meters tall, it has about 800,000 leaves (depending on the species), which corresponds to a leaf surface of 1600 square meters. To take care of them would be impossible in the cold, central european winter. So trees that switch to low flame in winter "cut the connection to the leaves", says thein.