We dress and do different things according to the environment. Just as you adjust to your environment, plants adjust to their environment. The tree for instance, loses its leaves in the fall. It is preparing for the winter. In the winter, the environment is cold and the ground is frozen.
Less sun means less food.
A frozen ground means less water. The tree adjusts to its environment. In the spring, the tree will grow new leaves. This could begin a study of learning the types of trees if time permits. A leaf collection is suggested as an outside activity.