Hello, I have gotten some really good answers here in the past so I thought I would pose another question. This one deals with trees. My question is decidious trees lose their leaves in the fall. What causes them to do this? Is it temperature, amount of sunlight etc. When the tree doesn't have leaves is it still alive and able to photosynthesis (my guess is no). If not how does it surive to the next spring and grow leaves again. What causes them to grow leaves again?