Wetland Management

Spikerush Meadow

Many areas of Lacreek National Wildlife Refuge that appear dry during the summer drawdowns, actually are covered by very shallow water. Properly managed, these areas grow species such as spikerush, that remain open and support abundant insect populations. Many species of birds, such as Virginia and sora rails, Wilson's phalaropes, white faced ibis, marbled godwits, willets, blue winged teal, and shovelers find this ideal for raising young.

The Refuge has 13 water impoundments creating nearly 5,400 acres of shallow flooded marsh and open water habitat. Water can be added or removed from each impoundment via water control structures. Controlled water level manipulations are one of the most effective ways to manage wetlands for migratory birds. Perennial flow of water coming onto the Refuge via Lake Creek, Cedar Creek, and Elm Creek coupled with the water control structures allow for moist-soil management opportunities. The term "moist-soil" refers to manipulating conditions within wetlands so that seeds from wetland plants (mostly annuals) can germinate, grow, and set seed.

Typically at the Refuge, the draw down stage will begin in late March and continue through early May. Draw downs during this time tend to maximize vegetation growth and seed production. In addition to the timing of the draw down, the rate of draw down plays an important role in determining which plants will grow. Generally speaking, all draw downs on the refuge are conducted at a gradual rate. Exposed mudflats, created by slowly drawing down water, provide quality food for migrating birds, especially shorebirds. As the growing season draws to a close, usually in early September, the moist soil units are shallowly flooded to provide food for migrating waterfowl. In addition, moist soil vegetation such as arrowhead produced during the summer months serves as important winter food resource for wintering trumpeter swans utilizing the Refuge.

Sagittaria Latifolia - Arrowhead

During the drawdowns, arrowhead, pictured here, and softstem bulrush often establish and grow on portions of the pools. The arrowhead grows very large leaves which capture the summer sun, and store this energy in underground tubers, which are similar to small potatoes. When freezing temperatures return, the above ground stems freeze off and create open water again. The underground tubers remain, and provide the most preferred natural foods for trumpeter swans. The bulrush roots and stems are a preferred food for muskrats, which use them to build winter lodges.