" the water freezes solid, the baby salamanders will die. It’s a good thing deciduous trees just happen to solve this problem. In winter, when there is very little warmth in the sun, bare branches allow a lot of warmth to penetrate. The movement of water over the uneven bottom also protects the stream from suddenly freezing. "

― Peter Wohlleben , The Hidden Life of Trees: What They Feel, How They Communicate: Discoveries from a Secret World