Analysis of A shadow cast from a hollowed shell

There stood a pair of willow trees.
Filled with life and all their leaves.
Days go by and seasons passed.
Both concured this cannot last.

While one stood mighty and tall.
The other's leaves began to fall.
Knowing the inevitable.
One was left miserable.

One tree watched the other crumble and fold.
Knowing the other tree was much too old.
Witnessing this unbearable hell.
The standing tree was left a hollowed shell.

Days go by and seasons passed.
Where once stood two trees a shadow was cast.
Left with nothing but a memory.
Now there stood just one tree.

Stuck beneath a lingering cloud.
The tree must remember the other was proud.
It enjoyed the life that they both shared.
It loved the other tree and always cared.

The sun rises wishing to expell
the shadow cast from the hollowed shell.
The skies open as rain begins to fall.
As if to answer the tree's call.

Where once stood a pair of willow trees
Filled with life and all their leaves.
Now stands a single tree, listening for
his whisper amongst the breeze.