The Flora of Dredged Material Sites in Navigation Pool 8 of the Upper Mississippi River

Book excerpt: A survey of vegetation growing on dredged material in Navigation Pool 8 of the Upper Mississippi River was made to determine plant species. Twenty-three dredged material sites in Pool 8 were surveyed and more than 3000 specimens collected of 304 species representing 64 plant families. Correlation of site ages, elevations, and plant community associations was used to determine primary colonizers of the various dredged material habitats. Sporobolus cryptandius (Torr.) Gray, Triplasis purpurea (Walt.) Chapm., Cyperus schweinitzii Torr., and Cycloloma atriplicifolium (Spreng.) Coult. were found to be pioneer herbaceous species of dry exposed dredged material sites. Upland invasion by woody species did not occur readily, but after a lengthy period species such as Vitis riparia Michx., Toxicodendron rydbergii Greene, and Rubus occidentalis L. encroached from surrounding forests. (Author).