Comparisons of Bird, Aquatic Macroinvertebrate, and Plant Communities Among Dredged Ponds and Natural Wetland Habitats at Long Point, Lake Erie, Ontario

Abstract Decreased wetland interspersion and need for dredging of lower Great Lakes coastal wetlands results from encroachment of open water by invasive cattail (Typha × glauca, T. angustifolia) and common reed (Phragmites australis). To increase wetland interspersion and fish and wildlife habitat a...
Ausführliche Beschreibung

Abstract Decreased wetland interspersion and need for dredging of lower Great Lakes coastal wetlands results from encroachment of open water by invasive cattail (Typha × glauca, T. angustifolia) and common reed (Phragmites australis). To increase wetland interspersion and fish and wildlife habitat at Long Point, Lake Erie, wetlands were dredged to restore open water ponds (0.4–4.0 ha ponds) in monotypic stands of cattail and common reed (hereafter cattail-reed), 2008–2010. We determined if bird, aquatic macroinvertebrate, and plant communities differed among dredged ponds, natural ponds, and areas of monotypic cattail-reed to investigate effects of dredging, May–August 2011. Marsh-bird relative abundance was 40 % greater at dredged and natural ponds than cattail-reed areas, and richness was at least 16 % greater at dredged ponds than natural ponds and cattail-reed areas. Relative abundance of macroinvertebrates was 77 % greater in dredged than natural ponds. Plant species richness was 57 and 54 % greater, respectively, and diversity 42 % greater at dredged ponds than natural ponds and cattail-reed areas. Our comparison of dredged ponds with natural wetland habitats highlights that dredging to restore interspersion and manage monotypic cattail-reed in lower Great Lakes wetlands can be beneficial to marsh-nesting birds and habitat resources used by fish and wildlife. Ausführliche Beschreibung