Counties: Oconto

Photos:

• Photo 1
• Photo 2
• Photo 3
• Photo 4

Charles Pond, 27 Aug. 2000. View across bay (formerly a pond cutoff by a baymouth bar). Photograph, E.J. Judziewicz.

Site Description

Charles Pond is a State Natural Area located along the west shore of Green Bay in southern Oconto County, south of the City of Pensaukee. Glaciolacustrine deposits of sand, silt and clay characterize the surficial geology of this site and the surrounding area. These lake sediments include associated deltas, low sand dunes, and organic deposits.

Charles Pond is a former bay-mouth bar lake. The site contains a swamp hardwood forest with a rich groundlayer, dominated by 6" - 12" trees (up to 24" d.b.h.) silver and sugar maples, green ash, basswood and swamp white oak. Patches of shrub swamp dominated by willow, alder, and red-osier dogwood are also present. A narrow strip of emergent marsh dominated by dense stands of soft-stem bulrush and broad-leaved cattail borders the bay. Closer to shore, the marsh grades into a narrow zone dominated by joe-pye weed, blue vervain and the invasive exotic plants purple loosestrife and common reed grass. The presence of these invasive plant species threatens the community integrity of the emergent marsh and shrub swamp.

This wetland is heavily influenced by water level changes in Green Bay and Lake Michigan. When Lake Michigan levels are low the pond is separated from the bay by a sand spit. During high water level periods the pond is reconnected to Green Bay. Inundation from the high water levels of the 1980's, and the accompanying disturbance, broke up much of the emergent marsh and shrub swamp and drowned low lying portions of the hardwood swamp. During low water years, exposed mud flats provide excellent migratory stopover habitat for many species of shorebirds and other waterfowl. Shrub swamps are common in many wetland areas on the West Shore of Green Bay, and serve as important migratory stopover areas for many migratory birds.

Additional Comments

This dynamic site changes dramatically over time. Curbing the spread of invasive species will require increased attention here. As with other wetlands on Green Bay's east shore Charles Pond is an important stopover area for migratory birds.