Freshwater swamp forests, or flooded forests, are forests which are inundated with freshwater, either permanently or seasonally. They normally occur along the lower reaches of rivers and around freshwater lakes. Freshwater swamp forests are found in a range of climate zones, from boreal through temperate and subtropical to tropical.
In the Amazon Basin of Brazil, a seasonally flooded forest is known as a várzea,, and refers to a whitewater-inundated forest. Igapó refers to blackwater-inundated forest.
Peat swamp forests are swamp forests where waterlogged soils prevent woody debris from fully decomposing, which over time creates a thick layer of acidic peat.