In the autumn, the green leaves on the trees change to a variety of different colors. What causes this to happen?
In one of the most colorful times of the year, autumn, the days get shorter and the nights become longer. Leaves of various trees change to various colors such as red, yellow, brown, violet, etc. But how do they do that and what causes this to happen? Let’s dig deep into that step by step.
- Chlorophyll and its process
Leaves on most plants and trees are green-colored because of a bright green chemical present in them known as chlorophyll. Chlorophyll is responsible for conducting photosynthesis i.e. absorbing the energy present in sunlight and turning it into glucose which the tree can use for its energy. In other words, chlorophyll helps trees make their food from sunlight.
- Other chemicals present
Apart from chlorophyll, the tree leaves contain various other colorful chemicals, called pigments, that are red, yellow, orange, purple, etc. These colorful pigments do their jobs too but only chlorophyll helps a plant make its food. This is the reason why chlorophyll is present in most parts of the leaves and shadows the other chemical pigments. This phenomenon makes the leaves green.
- In a nutshell
As summer ends and autumn begins, as the days get shorter, less amount of sunlight hits the tree leaves. The trees get a signal to stop making chlorophyll and sending water to the leaves.
As the chlorophyll diminishes, the green color starts to fade making room for other colors to become visible. As the trees change their color, they become dried up and begin to fall. They fall because chlorophyll which helps them make energy gets all used up and the collected energy flows into the trees. Hence, it helps them live through winters. This color-changing is a fascinating phenomenon and people often enjoy different shades of trees during autumn.
FAQs
- At which time of the year do the trees shed their leaves?
During autumn and winter, trees shed their leaves to survive through the winter by utilizing the saved up energy
- What causes leaves to change their color in autumn?
Leaves undergo a chemical change due to less sunlight shadowing chlorophyll and exposing other chemical pigments.
- Which type of trees shed their leaves in autumn?
Deciduous trees such as oaks, maples, birch, beeches, etc. are broad-leaved and shed their leaves in autumn.
- Why type of trees don’t shed their leaves in autumn?
Evergreen trees such as pine, spruce, and cedar trees stay green all autumn and winter. Their leaves are small and tough, usually called needles. They won’t cause the tree to lose water as bigger leaves do.
- What is the process of leaves changing color called?
The process of leaves changing colors is called photosynthesis. During autumn, the process of photosynthesis breaks down and chlorophyll gets used up. This process makes space for other chemicals to become visible.
- What are the three main factors that cause the leaves to change colors in autumn?
The three factors that influence autumn leaf color are - leaf pigments, weather, and length of the night.
