How do the trees and the ploughman build up the image of mortality in the poem 'at grass' by ted hughes?

In the poem "At Grass" by Ted Hughes, the trees and the ploughman symbolize the passing of time and the cycle of life. The timeless presence of the trees contrasts with the ploughman's labor, highlighting the impermanence of life and the inevitability of mortality. The image of the ploughman working the land suggests the constant cycle of life, death, and rebirth, emphasizing the theme of mortality in the poem.