Question

he plant the forest's heritage

Answer 1

i guess this comes from ; the heart of the the tree by henry bunner ....
STANZA 2 

He plants the glory of the plain;
He plants the forest’s heritage;

Trees are the main elements that make a plain area green and beautiful. So the poet describes trees as ‘the glory of the plain’. Moreover, today’s single tree may turn into a forest someday. So by planting a tree now the man plants a ‘forest’s heritage’.

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