 Deciduous plants were traditionally believed to shed their leaves in autumn primarily because the high costs involved in their maintenance would outweigh the benefits from photosynthesis during the winter period of low light availability and cold temperatures.In many cases, this turned out to be oversimplistic — other factors involved include insect predation, water loss, and damage from high winds or snowfall.Anthocyanins, responsible for red-purple coloration, are actively produced in autumn, but not involved in leaf-drop.