Polder and Peat bog

Polder noun - Low-lying land that has been reclaimed and is protected by dikes (especially in the Netherlands).

Peat bog and polder are semantically related in swamp topic. In some cases you can use "Peat bog" instead a noun "Polder", when it comes to topics like wet land covered with vegetation.

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.

Polder and peat bog are semantically related in swamp topic. You can use "Polder" instead a noun phrase "Peat bog", if it concerns topics such as wet land covered with vegetation.