Anoka Ecosystems:
Shrub Swamp
Shrub swamps are wetland ecosystems which occur in areas which are too wet to become hardwood swamps, but too dry or shallow to become marshes. Therefore, shrub swamps are considered mid-successional between wet meadows or fens and conifer or hardwood swamps. Shrub swamps typically occur on organic soils, such as muck and shallow peat soils.
Commonly, these swamps are created after a catastrophic event in a forested swamp, such as a flood or windstorm. Also, drained meadows and fens often progress to shrub swamps, and then to forested swamps. In Anoka, these ecosystems are most commonly found in expansive wetlands along slow streams on the sandplain and in shallow wetland basins.
The vegetation in this community is often determined by the fluctuation in water level and the presence of fire. The canopy is variable from very dense thickets to having many gaps consisting
of grasses and sedges. Shrubs
are tall and usually consist of speckled alder, willows and red-osier dogwood.
Sources:
"Minnesota's Native Vegetation: A Key to Natural Communities"
Version 1.5 Minnesota Department of Natural Resources, Natural Heritage
Program, 1993.
Wovcha, D., B. Delaney, and G. Nordquist. Minnesota's St. Croix Valley and Anoka Sandplain: A Guide to Native Habitats. MInneapolis: University of Minnesota Press, 1995.
