Marshes and Peat bog

Peat bog and marshes are semantically related. In some cases you can use "Peat bog" instead a noun "Marshes".

Peat bog noun - Wet spongy ground of decomposing vegetation; has poorer drainage than a swamp; soil is unfit for cultivation but can be cut and dried and used for fuel.

Marshes and peat bog are semantically related. Sometimes you can use "Marshes" instead a noun phrase "Peat bog".