biology question #3731
Chloe Jones, a 10 year old female from London asks on December 4, 2006,Q:
Why do trees lose their leaves?
viewed 13059 times
A quick websearch yields lots of answers. There are many reasons, but probably the main one goes like this. In winter, it's colder and darker than in summer. Since the leaves are the energy factories for trees, creating sugars from sunlight, carbon dioxide and water, they need warmth and light to work properly. As winter comes, the days get shorter and colder and the leaves cannot produce as much energy any more. Also, as winter comes so does lots of snow and wind and then the leaves can become a problem. If they catch too much snow or wind, a branch could break off, or the whole tree could be blown over. For these reasons, it's better for the tree to just get rid of its leaves for the winter months and shut down. When the days start getting longer and warmer, it puts out fresh new leaves. A good explanation can be found at Why do leaves fall off Trees? in A Year in the Wonderland of Trees
making a small donation to science.ca.