Phosphorus Retention in Intact and Drained Prairie Wetland Basins: Implications for Nutrient Export. Issue 4 (1st July 2018)

• Record Type: Journal Article
• Authors: Badiou, Pascal; Page, Bryan; Akinremi, Wole
• Is Part Of: Journal of Environmental Quality. Volume 47:Issue 4(2018)
• Page Start: 902
• Page End: 913
• Publication Date: 2018-07-01
• Subjects: Agricultural ecology -- Periodicals; Environmental engineering -- Periodicals; Pollution -- Periodicals; 630
• DOI: 10.2134/jeq2017.08.0336
• Languages: English
• ISSNs: 0047-2425

Abstract

Abstract : Draining of geographically isolated (no defined inlet or outlet) freshwater mineral soil wetlands has likely converted areas that acted historically as important P sinks to sources of P. To explore the role of wetland drainage on nonpoint‐source P pollution, differences in the chemical characteristics and P sorption parameters of drained and intact wetlands were investigated in a small watershed situated in the Prairie Pothole Region of southwestern Manitoba, Canada. Chemical characteristics and P sorption parameters varied across landscape positions, particularly for landscape positions that were submerged. Intact wetlands had slightly higher concentrations of organic and total P relative to drained wetlands, which is indicative of their P trapping capacity. More importantly, the maximum P sorption capacity and P buffering capacity of intact wetlands were 3.6 (1752 vs. 492 mg kg −1 ) and 17 (1394 vs. 84 L kg −1 ) times greater than those in drained wetlands. Conversely, equilibrium P concentrations and bioavailable P concentrations in drained wetlands were an order of magnitude greater than those in intact prairie wetlands. Our study suggests that intact prairie wetlands may be effective sinks for P. As a result, prairie wetlands may play an important role in mitigating nonpoint‐source pollution. Conversely, our findings suggest that drained prairie wetlands are potentially a high risk for P export and should be treated as important critical source areas within prairie watersheds. Core Ideas: Wetland drainage has converted P sinks to sources. Intact wetland sediment has higher P buffering capacity than drained wetlands. Wetland drainage increases nonpoint‐source P pollution.