ABSTRACT
Much of the available data is based on mass balance studies of individual wetlands, which reveal the overall function but do not provide insight into the hydrological and chemical processes that produce different patterns of chemical behavior. This chapter focuses on linkages between hydrological flow paths and chemistry as a conceptual framework for explaining differences in the roles of wetlands as sources, sinks, and transformers of elements. However, most wetland studies have focused on the quantification of hydrological inputs and outputs for element mass balances rather than on the relationship between hydrology and chemical transformation processes. Differences in residence time and the environment associated with various surface and subsurface hydrological pathways within wetlands can influence element retention. Both external and internal hydrological pathways determine whether a wetland is an element sink or source. The hydrological links between Plastic and Harp wetlands and their catchments have been previously considered within a landscape framework that emphasizes a physiographic continuum of overburden depth.
