The Neosho River floodplain was once covered with hundreds of shallow wetlands that dried from spring into summer, allowing seed-producing plants to grow, and then were recharged by fall rains, providing migrating waterfowl with food and cover. Although most of these natural wetlands are gone, the Refuge has built new wetlands called moist soil units that are managed to mimic this natural wet and dry cycle. These areas are intensively managed with levees, pumps, and water control structures; in the fall they fill with rainwater or water pumped from the Neosho River and Eagle Creek, and in late spring water is slowly released so wetland plants such as smartweed, pigweed, and bidens can grow and produce seeds before the wetlands are filled again the next fall. When flooded, these plants and their seeds provide waterfowl with high-energy food for journeys between wintering and breeding grounds. Because moist soil plants produce the most seeds early in their life cycle, discing, mowing, and prescribed fire are used to remove older plants, stimulate new growth, and discourage tree growth. These wetlands also support many other wildlife species, as frogs and small fish feed hawks, egrets, and herons, beetles and snails provide protein for shorebirds, and the food produced there gives many birds the protein needed for migration and to produce young.