Shrub swamp

Shrub swamps — also called scrub swamps or buttonbush swamps — are a type of freshwater wetland ecosystem occurring in areas too wet to become swamps ("true" or freshwater swamp forest), but too dry or too shallow to become marshes.^[1][2] They are often considered transitional ("mid-successional") between wet meadows or fens and conifer or hardwood swamps.

By some classifications,^[which?] shrub swamps must have at least 50% shrub cover and less than 20% tree cover. Other definitions^[which?] specify large shrubs with small trees less than 35 feet (11 m) in height. Creation of shrub swamps often follows a catastrophic event in a forested swamp (flood, cutting, fire, or windstorm). Another route of development is via drained meadows and fens which progress to shrub swamps as a transitional state to forested swamps.