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Sediment phosphorus buffering in streams at baseflow: A meta‐analysis
Author(s) -
Simpson Zachary P.,
McDowell Richard W.,
Condron Leo M.,
McDaniel Marshall D.,
Jarvie Helen P.,
Abell Jonathan M.
Publication year - 2021
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.1002/jeq2.20202
Subject(s) - sediment , baseflow , hydrology (agriculture) , phosphorus , environmental science , streams , eutrophication , environmental chemistry , surface water , sorption , water quality , pollution , anoxic waters , chemistry , drainage basin , environmental engineering , nutrient , ecology , geology , streamflow , adsorption , paleontology , computer network , cartography , geotechnical engineering , organic chemistry , computer science , geography , biology
Phosphorus (P) pollution of surface waters remains a challenge for protecting and improving water quality. Central to the challenge is understanding what regulates P concentrations in streams. This quantitative review synthesizes the literature on a major control of P concentrations in streams at baseflow—the sediment P buffer—to better understand streamwater–sediment P interactions. We conducted a global meta‐analysis of sediment equilibrium phosphate concentrations at net zero sorption (EPC 0 ), which is the dissolved reactive P (DRP) concentration toward which sediments buffer solution DRP. Our analysis of 45 studies and >900 paired observations of DRP and EPC 0 showed that sediments often have potential to remove or release P to the streamwater (83% of observations), meaning that “equilibrium” between sediment and streamwater is rare. This potential for P exchange is moderated by sediment and stream characteristics, including sorption affinity, stream pH, exchangeable P concentration, and particle sizes. The potential for sediments to modify streamwater DRP concentrations is often not realized owing to other factors (e.g., hydrologic interactions). Sediment surface chemistry, hyporheic exchange, and biota can also influence the potential exchange of P between sediments and the streamwater. Methodological choices significantly influenced EPC 0 determination and thus the estimated potential for P exchange; we therefore discuss how to measure and report EPC 0 to best suit research objectives and aid in interstudy comparison. Our results enhance understanding of the sediment P buffer and inform how EPC 0 can be effectively applied to improve management of aquatic P pollution and eutrophication.