Question

Why do leaves turn red and shed off during the autumn season?

Answer 1

Autumn marks a transition of change of summer to winter, it occurs outside the tropical regions. It occurs when days become short and nights get longer. Plants get less sunlight and therefore there is a transition in the color of leaves in this season.

Complete answer:
Many of the trees shed their leaves as a strategy to survive harsh weather circumstances. Trees like Ash, Birch, Maple, Oak, etc. shed their leaves for part of the year. These trees have broad leaves that are vulnerable to damage during dry and cold weather conditions.

Shedding of leaves is one of the natural processes that occur concerning prevailing weather conditions. Most of the time shedding leaves is a strategic action to survive harsh weather. Shedding of leaves helps the trees to conserve water and energy. Specialized cells cause the act of abscission that is triggered by various plant hormones and this results in the shedding of leaves.

Trees reabsorb valuable nutrients from the leaves before shedding them. The nutrients stored are for future use when unfavorable conditions arrive. Trees turn red or orange during the fall as chlorophyll which gives green color to leave is the first unit to be broken down for energy. The exposed areas from where leaves are cut off are covered by a protective layer of cells.

Note:
Trees turn red or orange during the fall as chlorophyll which gives green color to leave is the first unit to be broken down for energy. Shedding of leaves also provides uninterrupted pollination of flowers in future springtime. The air-blown pollen finds it easy to pollinate the female flowers without leaves getting in the way. Thus, the shedding of leaves is an important natural event that must occur for the sustainability of deciduous trees.