@article{moorberg_vepraskas_white_richter_2023, title={Phosphorus Fluxes in a Restored Carolina Bay Wetland Following Eight Years of Restoration}, volume={43}, ISSN={["1943-6246"]}, DOI={10.1007/s13157-023-01725-z}, abstractNote={Restoring wetlands on agricultural land can release soil phosphorus (P) to surface waters. Phosphorus is a limiting nutrient in many freshwater systems, thus restricting its release will improve surface water quality by preventing algal blooms. A P balance was used to examine how P was cycling in a Carolina Bay wetland eight years after restoration from prior-drained agricultural land. The change in soil P was evaluated between archived samples taken at restoration (2005), and eight years after restoration (2013). Measured P fluxes included atmospheric deposition, plant uptake, and loss to surface water outflow. The soil total P pool at the time of restoration was 810 kg P ha−1. No significant (α = 0.05) decrease in the soil P pool was observed over the eight years. Atmospheric deposition contributed 1.0 kg P ha−1 yr−1, plants incorporated 3.3 P ha−1 yr−1 into woody biomass and 0.4 kg P ha−1 yr−1 as forest floor litter, and 0.2 kg P ha−1 yr−1 was lost to surface waters draining the wetland. Because the loss of P to surface waters was small, and because runoff water concentrations of P declined through this period of study to concentrations below those likely to cause eutrophication (< 0.1 mg L−1), we concluded that the wetland was not contributing to the degradation of surface water quality of nearby streams following restoration. Further, isolated wetlands such as that studied may be promising sites for future wetland mitigation projects due to limited impacts on surface water quality.}, number={6}, journal={WETLANDS}, author={Moorberg, Colby J. and Vepraskas, Michael J. and White, Jeffrey G. and Richter, Daniel D.}, year={2023}, month={Aug} }
 @article{moorberg_vepraskas_niewoehner_2013, title={Dynamics of P dissolution processes in the matrix and rhizospheres of bald cypress growing in saturated soil}, volume={202}, ISSN={["1872-6259"]}, DOI={10.1016/j.geoderma.2013.03.017}, abstractNote={Phosphorus release to ground or surface waters is commonly observed in wetlands that were restored on previously drained and farmed land, but the precise location of where the P is dissolved within the soil is unknown. This study compared the concentration of dissolved P in both the rhizospheres and soil matrix under saturated conditions. Experiments were conducted in rhizotrons (glass-walled boxes) which were filled with Ap horizon material from an Aeric Alaquod in a restored wetland. Phosphorus release was monitored from the rhizospheres of bald cypress roots (Taxodium distichum, L.), and an unplanted control representing the soil matrix. The rhizotrons were saturated for 120 days, and soil water was collected twice monthly at three depths. Numbers of live and dead roots were determined monthly. Following saturation, vigorous root growth was observed near the surface (0 to 22 cm depth) throughout the 120 days saturation period, while up to 30% of the roots in the lower layer (41 to 59 cm depth) died after 20 days of saturation. Rhizosphere processes did not increase P concentrations in the soil solution compared to the matrix controls. In the top layer of the planted treatment dissolved total P concentrations were 3.5 times lower than matrix concentrations (peak DTP of 700–900 μg P L− 1””) due to oxygen loss by root aerenchyma. Significantly larger amounts of dissolved organic C and Fe2 + were found in the rhizospheres than the matrix. Dissolved total P concentrations in the rhizosphere were equal to DTP concentrations in the matrix during the first 54 days of saturation, but lower than those of the matrix thereafter, most likely due to plant uptake. These findings indicate that under saturated conditions plant rhizospheres do not cause more P to be released to the soil water over that of the matrix, and may contain lower amounts of P than the soil matrix due to plant uptake. These results pertain to soils having an organic C concentration of at least 26 g kg− 1 or higher.}, journal={GEODERMA}, author={Moorberg, Colby J. and Vepraskas, Michael J. and Niewoehner, Christopher P.}, year={2013}, month={Jul}, pages={153–160} }