Most people know the old puzzle about a tree falling in an empty forest, and this poem answers it bluntly: yes, of course it makes a sound. The speaker sounds impatient at first, calling the question "stupid," and the argument is simple. Just because you didn't hear something doesn't mean it didn't happen.
Then the poem widens out. Closing our ears to the world doesn't stop things from happening, whether we want them to or not. The tree becomes a way of talking about everything we choose not to notice.
The last lines shift the tone from irritation to tenderness. The speaker invites us to listen, and what we'd hear is "the cry of the forest" mourning one of its own. By treating the forest as a community that grieves, the poem turns a logic puzzle into a plea for attention and empathy. The mood moves from sharp and dismissive to quiet and sorrowful.