The essential ingredient is that the pond has no fish. Swamps A cypress dome is an anomalous southern deepwater swamp type that is typically precipitation versus surface water, dominated.
Cypress domes typically exist as isolated depressions in very gently sloping landscapes.
Fens, like bogs, tend to be glacial in origin and are found in the northern United States or on mountains and mountainsides. Fens are dominated by herbaceous plants, such as grasses and sedges, typically lack the Sphagnum moss that predominates in bogs, and look like meadows. Fens are less acidic than bogs because they have little or no Sphagnum, and because ground water inputs tend to be neutral or alkaline, pH 4.0 - 8.0 Higher primary productivity and a greater variety of flora and fauna than bogs. Although waterfowl such as ducks and herons are commonly associated with marshes, other birds, such as songbirds and hawks, also feed on the life generated within wetlands. Southern deepwater swamps are riparian systems notable for the standing water present during much of the year.