What does the felled maple tree in "In Memory of a Maple Tree" symbolize?

The image of "maple tree" in the poem symbolizes the image of a generation of great national heroes who fought bravely in a specific historical period.

The felled maple tree: not only symbolizes every outstanding individual of the Chinese nation that has been tortured and gone through many vicissitudes of life, but also symbolizes the nation and motherland that had a glorious past but are now devastated.