Why do plants shed leaves?

1. Internal cause: After a certain period of physiological activities, a large number of metabolites, such as minerals, accumulate in cells, causing physiological function decline and death (chlorophyll destruction).

2. External factors: the cold weather, lower soil temperature, reduced rainfall, and greatly weakened water absorption capacity of roots.

There are two kinds of fallen leaves:

1, whenever the drought or cold season comes, all the leaves die and fall off, leaving only branches, which are deciduous trees, such as peaches.

2. After new leaves appear in spring and summer, the old leaves gradually fall off. As far as the whole tree is concerned, it is evergreen all year round and is an evergreen tree, such as Cinnamomum camphora. ?

Extended data:

When autumn comes quietly, the air becomes dry, and the water in the leaves evaporates through many gaps on the surface of the leaves. At the same time, due to the cold weather, the role of tree roots is weakened, and the water absorbed from the ground is reduced, making water in short supply. In this way, the tree will soon die, and in order to survive, a separation layer will be formed at the joint between the petiole and the branch.

After the separation layer is formed, it will break when a slight breeze blows, so the leaves will fall. Of course, there is a protective layer inside the shedding layer to protect the leaves from viruses. At this time, water is no longer transported to the leaves. After the leaves fall off, there are bare branches left, so the water consumption of trees is reduced, which makes the trees safe for the winter, so it is also beneficial to the trees to fall off their leaves.

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