Swamps do not have the best public image. Movies like "The Swamp Thing" and place names like "The Great Dismal Swamp" convey a foreboding landscape. However, the term swamp simply refers to a wooded wetland. Based on dominant vegetation, Michigan's swamps can generally be divided into three different types
- conifer swamp with tree species such as tamarack, cedar, or balsam fir
- hardwood swamp with tree species such as red maple, black ash, American elm, or balsam poplar
- shrub-scrub swamp with shrub species such as tag alder, willows, or dogwoods
Swamps are usually inundated or saturated periodically at some point during the growing season.
Some types of swamps, such as a red maple floodplain forest, are associated with lakes, rivers, or streams: others are associated with areas where the ground water is near the soil surface. The soils in swamps are usually rich in nutrients and organic matter. This is due to silt and organic matter deposited by flood events and the accumulation of organic matter (dead trees and other vegetation) over time.
A unique type of wetland that occurs in forests, but may not be recognized as a swamp due to its small size, is a vernal pool. Vernal pools are small isolated wetlands that only hold water for a short time during the spring. After snowmelt, amphibians congregate in vernal pools to create another generation of frogs, toads, and salamanders. By midsummer, the water is gone from this important, yet ephemeral, wetland.
Swamps provide very important habitat for a wide array of wildlife throughout the year, including deer, bear, raccoons, bobcats, eagles, songbirds, and other small animals. The dense vegetation and proximity to surface water (especially along rivers) allow for high nutrient exchanges between land and water ecosystems. These factors also contribute to the value of swamps as cover and food sources for many animals.