What does "the imprint of nature" mean in poetry?

Of fallen leaves.

"Stamps of Nature" is selected from the Chinese text of the first grade of primary school. The full text is as follows:

In spring, buds and petals grow on trees;

Trees in summer are full of plump leaves;

Trees in autumn are covered with bright red and golden leaves;

Under the trees in winter, leaves fall to the ground and become soil.

Leaves are nature stamps, which are sent to you all year round.

Send it to me, to everyone.

Extended data

The poem "Stamps of Nature" takes fallen leaves as a reference, and writes about four seasons in a year, namely, spring, summer, autumn and winter, and summarizes the characteristics of leaves in the four seasons. On trees in spring, leaves are characterized by buds. On trees in summer, leaves are characterized by fat leaves; Autumn leaves are characterized by bright red and golden yellow; Under the trees in winter, the leaves are characterized by falling leaves all over the ground.

In this paper, leaves are compared to stamps to show people the changes throughout the year. People perceive the arrival of four seasons through the changes of leaves.

Deciduous leaves were originally just a natural phenomenon. They grow in spring and flourish in summer. In autumn, most deciduous plants and trees begin to shed leaves, and the leaves are yellow and curly, falling from the trees and dancing with the wind. It also means that after late autumn, winter is coming. However, in the article, the author uses vivid metaphors to show readers the differences between the four seasons, describes different scenes in different seasons, and expresses his love for nature.