Dormancy of a tree is a period of time when the tree is alive but not actively growing. It is a survival adaptation that allows the tree to cope with harsh environmental conditions, such as cold temperatures, short days, and low water availability. During dormancy, the tree slows down its metabolism, stops producing leaves and flowers, and develops cold hardiness. Dormancy is triggered by changes in light and temperature that are sensed by the tree's photoreceptors and hormones. Dormancy helps the tree conserve energy and protect itself from damage until favorable conditions return in spring.