Why do Leaves fall off Trees?
Why do trees lose their leaves in autumn?
During autumn season the earth receives immense sunlight and warmth. This results in trees shedding off their leaves in order to prepare themselves for the cold winter months. Trees that shed their leaves for a part of the year are known as deciduous trees and trees that do not shed their leaves are known as evergreen trees.
What do leaves do for trees?
Many trees shed their leaves to survive the harsh winter conditions. Shedding their leaves help trees to conserve water and energy. As the harsh weather conditions approach, the hormones in the trees start a process known as abscission. In this process the leaves are purposefully cut off from the tree branches by specialised cells. Before the abscission process starts the trees absorb all the essential nutrients and food from the leaves and store them in their roots for later use. Chlorophyll is the first essential nutrient that is absorbed by the trees. Thus leaves lose their green colour before shedding off. If you notice; during the fall season, the leaves change into red, orange or yellow in colour.
What will happen if leaves don’t fall off the trees?
Trees also lose water through the pores in their leaves. So during the cold, dry winter months, water retention becomes critical and thus there is no use for the leaves. So they cut off their leaves. If leaves remained on trees, the water in the leaves would freeze in the winter. Frozen, solid leaves would die eventually. This means that when spring would arise, the tree would have dead leaves and the tree would also die soon. The process of losing leaves so that new leaves can grow after the winter months prolongs the life of a tree and thus this cycle should continue.