The Relationship of Soil Parameters and Root Metabolism to Primary Production in Periodically Inundated Soils

Hydrology is the dominant forcing function in wetland ecosystems (Gosselink and Turner 1978). Through its direct effect on soil waterlogging, the dynamic hydrologic environment controls soil physicochemical status, sedimentation rates, salinity, nutrient cycling, decomposition, and faunal and microfloral activities. Thus soil waterlogging controls the interaction of soil and root processes which, in turn, influence growth (Figure 34.1). Although wetland vegetation is highly productive, the roots of these plants often experience severely reduced soil conditions, lack of oxygen, and toxic compounds as a result of soil waterlogging. This chapter emphasizes the linkage between growth responses and waterlogging-induced changes in root processes of wetland vegetation. While not exhaustive, the examples in Tables 34.1-34.5 illustrate the major soil-root interactions which influence growth. In addition, we present a case study describing how hydrologically induced changes in soil parameters affect root processes and ultimately growth and productivity of Spartina alterniflora the dominant intertidal salt marsh angiosperm of the Atlantic and Gulf Coasts of the United States