what is the relation between art and nature in the poem of bizentium

Nature and art seem a natural progression to the poet. Yeats begins his poem full of youth and life, "The young in one another’s arms, birds in the trees..." This soon gives way to images of death, the underbelly of life. Art seems to appease the poet. Art, unlike his body, does not change. Art is a way to capture the youth. With art, the flower need not wither away and die; it can remain in its glory for generations to appreciate. Similarly, no matter what one's age is, art can be expressed from within the nature of the soul. The whole "you can be young inside" adage comes to mind. The speaker uses art and nature to transcend the boundaries of our "mortal coil" (that's my quote from Hamlet!!) The combination of art and nature brings the poet into the realm of the spiritual.