Effect of root oxygen stress on phosphorus uptake by cattail

The effect of redox conditions or oxygen demand in rooting medium on phosph orus (P) uptake by Typha domingensis was quantified; Phosphorus uptake decr eased with decrease in redox potential in the rooting medium. Greatest upta ke was measured under the oxidized treatment (+565 mV). Phosphorus uptake w as less under the two anaerobic treatments (+277 mV and -200 mV). In the tw o anaerobic treatments, P uptake was considerably less at -200 mV in which a high oxygen demand was created using titanium (Ti3+) citrate. Results sug gest that P uptake by Typha domingensis in wetland receiving P input from a djacent agriculture areas could be influenced by the oxidation-reduction St atus of the root environment.