Invertebrate egg and plant seed banks in natural, restored, and drained wetlands in the Prairie Pothole Region (United States of America) and potential effects of sedimentation on recolonization of hydrophytes and aquatic invertebrates

Sediment from agricultural sources is the major pollutant of aquatic ecosystems in the United States and it poses unique threats to wetlands of the Prairie Pothole Region (PPR). Agricultural sedimentation and disturbances (e.g., cultivation) may bury or decimate invertebrate and plant propagules important for successional changes throughout interannual climate cycles and/or reduce pool depths which may impede recovery of wetland communities in restored wetlands. I evaluated the effect of sedimentation on loss of wetland volume, and the effect of sediment load on emergence of plants and invertebrates. Additionally, I compared the seed and invertebrate egg bank composition of high quality reference wetlands with no history of cultivation to previously farmed nondrained, restored, and drained seasonal and semipermanent wetlands in the PPR.; Previously farmed wetlands had greater mean (+/-SE) sedimentation rates (0.26 +/- 0.02 cm yr-1) than reference wetlands (0.08 +/- 0.03 cm yr-1). Projected over the next 200 years, farmed and reference wetland sedimentation rates would result in a 57% and 18% loss, respectively, in the number of wetlands capable of attaining water depths ≥1 m. Over the same time, 50% and 20% of the wetland volume would be lost under farmed and reference wetland scenarios.; Burial of seed and egg banks with 0.5 cm of sediment virtually halted invertebrate and seedling emergence. Drained and restored wetlands had poorer hatching success of invertebrates than nondrained and reference wetlands, however this varied by wetland class. Most restored seasonal wetlands contained viable invertebrate egg banks 5-years post-restoration, but taxon richness and invertebrate abundance did not increase with restoration age. For both wetland classes, reference wetlands had greater perennial seed density, taxon richness, floristic quality, and fewer annual species than nondrained, restored, and drained wetlands, whereas seed bank composition varied little among previously farmed wetlands. Floristic quality of seed banks in restored wetlands did not increase with restoration age.; Agricultural activities in the PPR have impacted seed and invertebrate egg banks, and have caused significant loss in wetland volume and depth that potentially alters success of wetland restorations. Agricultural conservation strategies need to be implemented to conserve wetlands in agricultural landscapes.