Wetlands Forest Communities as Indicators of Flooding Potential in Backwater Areas of River Bottomlands

A phytosociological study was made of forest types that occur in backwater and river bottomlands of the Gulf Coastal Plain, Arkansas Valley, and Mississippi Delta Regions of Arkansas. Twenty different forest types dominated principally by a single species were identified and described. Their occurrence was then correlated with flooding conditions in their habitats and the types were arranged along decreasing moisture gradients. Those forest types tolerant of flooding or saturated soils between three months to a year or more are Taxodium distichum, Nyssa aquatica, Cephalanthus occidentalis, Salix nigra, and Planera aquatica types. Those tolerant from one to three months are Forestiera acuminata, Carya aquatlca, Quercus lyrata, and Fraxinus pennsylvanica. Those tolerant between one month and two weeks are Populus deltoides, Celtls laevigata, Ulmus americana, Acer negundo, Carya illinoensis, Quercus nutallii, Liquidambar styraciflua, Quercus phellos, Quercus nigra, Carya ovata and Quercus falcata var. pagodaefolia. It is concluded that forests of the study area are similar in vegetation composition to those of wetlands in Mississippi and Louisiana and that the same types occupy comparable habitats. Principal differences are that comparable wetland types in Arkansas usually cover less area and tend to support more species characteristic of drier habitats