Leaves are what give plants their strength. They use the energy from the sun to turn air and water into sugars, which feed the plant. This process is called photosynthesis. So, if there isn’t enough water around, the leaves can’t do their job or get hurt, making the planet worse off. So, if they have to choose, plants would be better off without these expensive support organs.
They can also dispose of them after a single summer’s use when they might be degraded or infested with harmful leaf-eating animals, fungi, or viruses. Damaged leaves from harsh winter storms are also less useful come springtime.
As the days get shorter and the air gets cooler, the leaves on trees change from green in the summer to orange, yellow, red, and brown in the fall. It’s autumn. Soon, the leaves will fall to the ground… or won’t they?
The simple answer is that trees lose their leaves so they can live through the winter. So, we now know. Leaves fall or are pushed off trees so that the trees can survive the winter and grow new leaves in the spring. But the word “fall” doesn’t tell the whole story. It sounds like the trees aren’t doing anything, but they are actively “pushing” the leaves off their branches at this time of year.
What is deciduousness?
Trees that lose their leaves every year or at a certain time of year are called “deciduous.” Deciduousness happens most of the time in three situations.
The second type of deciduousness is “dry-deciduousness,” which is caused by dry weather in warm or hot climates.
Between the rainy seasons, which bring most of the year’s rain, many tropical and subtropical places can go for long periods without rain. During these dry periods, the trees lose their leaves and the forest dries out. For example, during the long dry season, which can last more than four months, many trees in the coastal forests of East Africa lose their leaves.
A plant will make every effort to salvage as many important components as it can from its leaves before it drops them.
Why do leaves change color?
The leaf begins to take on a brown color and develop a crunchy texture as it dries out. When it reaches this point, it drops from the tree.
The first component to be salvaged is chlorophyll, which is the light-gathering structure that is responsible for giving green color to leaves. Other chemicals and colors in the leaves become apparent as the chlorophyll is reclaimed from the leaf and absorbed back into the plant. This process takes place over the course of several days.
