An evaluation of soil phosphorus storage capacity (SPSC) at proposed wetland restoration locations in the western Lake Erie Basin

Historical loss of wetlands coupled with excess phosphorus (P) loading at watershed scales have degraded water quality in portions of the western Lake Erie Basin (WLEB). In response, efforts are underway to restore wetlands and decrease P loading to surface waters. Because wetlands have a finite capacity to retain P, researchers have developed techniques to determine whether wetlands function as P sources or sinks. The following technical report evaluates the soil P storage capacity (SPSC) at locations under consideration for wetland restoration in collaboration with the Great Lakes Restoration Initiative (GLRI) and the H2Ohio initiative. Results indicate that the examined soils display a range of P retention capacities, reflecting historic land-use patterns and management regimes. However, the majority of study locations exhibited some capacity to sequester additional P. The analysis supports development of rankings and comparative analyses of areas within a specific land parcel, informing management through design, avoidance, removal, or remediation of potential legacy P sources. Additionally, the approaches described herein support relative comparisons between multiple potential wetland development properties. These results, in conjunction with other data sources, can be used to target, prioritize, justify, and improve decision-making for wetland management activities in the WLEB.