What is the reducing effect of fallen leaves in autumn?

Falling leaves in autumn is to reduce water loss of leaves and energy waste of photosynthesis.

Data expansion:

I. Background introduction

Autumn is the season when trees go into dormancy. Leaves begin to turn yellow, wither and finally fall. This phenomenon is called "defoliation" in botany. In order to understand the causes of falling leaves in autumn, we need to explore its influence on leaves.

Second, reduce water loss.

1. transpiration: leaves transpiration through stomata, thus releasing water into the atmosphere. In autumn, the temperature drops, the water evaporation rate is relatively low, and the water supply in the soil is relatively reduced. Therefore, leaving leaves will lead to excessive water loss and increase the drought stress of trees.

2. Cold adaptation: Falling temperature in autumn may cause freezing injury and damage trees. Leaves are one of the most vulnerable parts of trees. Trees can reduce the damage caused by cold weather by letting leaves fall.

Third, reduce energy waste.

1. Photosynthesis: Leaves are the main organs of photosynthesis. By absorbing sunlight and carbon dioxide, they are converted into energy and nutrients. However, under the conditions of weak sunshine and low temperature in autumn, the efficiency of photosynthesis is reduced, and the energy collection and transformation of leaves are also reduced accordingly.

2. Nutrient transport: trees need to redistribute limited nutrients and water to more important parts, such as roots and seedlings, in order to get enough nutrients and water supply in winter. Fallen leaves can help trees recover and store nutrients and provide conditions for growth in the coming year.

Fourth, adapt to the needs of survival.

Falling leaves in autumn is a natural survival strategy for trees. By reducing water loss and energy waste, trees can better adapt to the cold environment and limited resources, enhance their viability and resist winter adversity.

To sum up, the purpose of defoliation in autumn is to reduce the water loss of leaves and the energy waste of photosynthesis. This is a natural adaptation strategy of trees, which helps them better adapt to the cold environment and the limitation of limited resources, thus improving their viability and resisting winter adversity.