Deciduous

the process by which the blades are separated from the mother. For most plants, leaves fall off after a mature aging process. Drought, low temperatures, extreme shade and pests often lead to early deciduous leaves. Tempered deciduous trees in the pre-winter sun induced, causing the whole leaves to fall off, which is conducive to the poor conditions through the winter. Because it is difficult for plants to absorb water in the frozen soil in winter, the winter sun is still abundant and often windy, so the steaming effect can be quite strong. Leaves fall off before winter to minimize the area of steaming and maintain moisture balance in the body. At the same time before shedding, the nutrients in the leaves have been transferred to the stem for storage for the growth and utilization of new leaves in the coming year. Therefore, autumn wind sweeping leaves is an adaptation in the long-term evolution of plants. Leaf shedding usually occurs in the base of the leaf handle is connected to the stem, this part is called the off-zone. When the leaves are about to fall off, the metabolism of the cells in the off-zone changes, close to the cell wall on the side of the shank, the adhesive layer actively decomposes, causing the cells to separate from each other, when the leaves are connected only by the tube bundle. There may be no fiber in the off-zone tube bundle, so the support is unusually weak, and the leaf falls off when the connection between the tube bundle breaks under the weight of the leaf itself and other mechanical forces such as wind swaying. After deciduous leaves, the wei tube bundle break is closed for intrusive filling or gum, and a wooden bolt clump is formed on the residual foundation of the leaf handle to protect the deciduous leaves from germs and prevent water loss.