"Mametz Wood" uses alliteration to great effect throughout. The first example is in line 1:
For years afterwards the farmers found them —
These /f/ sounds ring together as if the reader is discovering them as the line progresses, each one an obvious and sudden presence. This mimics the way the farmers accidentally find body parts in the soil. Indeed, the visual height of the /f/ also makes them look as though they stick out of the line, poking above the average height of the other letters.
In the following stanza, alliteration is again obvious:
A chit of bone, the china plate of a shoulder blade,
the relic of a finger, the blown
and broken bird’s egg of a skull,
The two /ch/ sounds have a sharp feel, conveying the sharp fragments of bone found in the earth. This sound also gently echoes the noise of machine gun fire. Indeed, the /b/ sounds that follow in the next two lines also feel somewhat violent and noisy, helping the stanza to subtly hint at the sensory terror that comes with warfare.
The next key examples of alliteration are in the fourth stanza, which describes the earth as:
reaching back into itself for reminders of what happened
like a wound working a foreign body to the surface of the skin.
These sounds are part of a key metaphor in the poem, in which the earth is compared to a human body. And, like a human body, the earth is trying to get rid of its "foreign" objects. The progression from alliterative /r/ to /w/ to /s/ sounds, then, represents the movement of "a foreign body to the surface of the skin" (or the ground). The sounds themselves even move from the throat (the /r/ sound) to the tip of the tongue (the /s/ sound), as if the trying to work their way out of the mouth. Additionally, the shared sounds are suggestive of small and somewhat difficult movements. Throughout the poem, then, alliteration helps capture the powerful aftermath of war and its effects on the natural landscape.