Inventory and vegetation classification of floodplain forest communities in Massachusetts

Floodplain forests on eleven rivers in Massachusetts were sur veyed to determine the variation in vegetation and soils across a range of hydrologic, physiographic, and climatic conditions. Quantitative vegetation data collected from 124 plots at 43 sites were analyzed using TWINSPAN and DECORANA (DCA), and six community types were identified. The six types were: Type I-Riverine island floodplain forests (Acer saccharinum-Populus deltoides-Acer negundo-Matteuccia struthiopteris association); Type II-Major-river floodplain forests (A. saccharinum-P. deltoides-Laportea canadensis association); Type IF-Transitional floodplain forests (A. saccharinum-Arisaema dracontium association); Type IV-Small-river floodplain forests (A. saccharinum-Fraxinus pennsylvanica-Quercus palustris association); Type V-Alluvial swamp forests (Acer rubrum-A. saccharinum-Q. bicolor association); and Type VI-Alluvial terrace forests (A. rubrum-Carya ovata-Prunus serotina association). The most common herbaceous taxa throughout all community associations were M. struthiopteris, L. canadensis, Boehmeria cylindrica, and Onoclea sensibilis. Results of the classification showed variation in floodplain forest vegetation composition among rivers in Massachusetts corresponding to significant differences in soil mottling, soil texture, presence/absence of a surface organic layer, and soil pH.