Coniferous swamps are forested wetlands in which the dominant trees are lowland conifers such as northern white cedar (Thuja occidentalis). The soil in these swamp areas is typically saturated for most of the growing season and is occasionally inundated by seasonal storms or winter snow melt.
The substrate is usually organic in nature and may contain peat in varying amounts or be composed entirely of muck. The swamp substrate is typically nutrient rich and neutral to alkaline but can be acidic and nutrient poor.
Coniferous swamps vary in composition, with different species of conifer dominating, and varying amounts of deciduous hardwoods growing within the swamp. A wide diversity of plants is represented within the swamp with certain species dominating in a variety of microhabitats dependent on factors such as available sunlight (as in cases of trees downed by wind or disease), soil Ph, standing groundwater, and differences of elevation within the swamp such as tussocks and nurse logs.