Why Do Some Trees Lose Their Leaves and Others Don't?

Some trees, like the oak and maple, lose their leaves in winter because they need to save energy. They let go of their leaves so they don’t have to keep them warm during cold months. Other trees, like pine and fir, stay green all year because they have special kinds of leaves that can handle the cold. Tree leaf shedding is like a yearly switch, some trees take off their clothes for winter, others wear them all year long.