The Pixley National Wildlife Refuge was established in 1959 by executive order to provide wetland habitat for migratory waterfowl and shorebirds. Of the 6,939 acres that comprise the Refuge, approximately 5,350 is upland habitat made up of grassland, alkali playa, and vernal pool habitat, 755 acres consists of seasonal wetlands, and 15 acres consist of riparian habitat.
Moist Soil Units
Water is a critical component of wetland management, including not only quantity but also timing and availability. Historically, due to the lack of a dependable water source, the refuge could not provide quality waterfowl habitat. It wasn't until 1992, when Congress passed the Central Valley Project Improvement Act that the refuge was provided with a reliable annual water allocation. Additionally, through a partnership with Ducks Unlimited in 1994, a deep well was drilled that produces sufficient water for the refuge to flood and maintain approximately 300 acres of seasonal wetlands.
All wetlands are seasonal in nature. Fall flood-up begins in mid-August and reaches a peak by October. Habitat is maintained through February after which a slow draining of the wetland begins. Selected units are irrigated during the late spring and early summer months to encourage plants to grow to provide food for wintering and migrating birds the following fall. Moist soil areas of Pixley Refuge are covered by shallow water depths (less than 6" deep). They are maintained by irrigation in the late spring and summer to encourage food plant growth. Swamp Timothy, watergrass, and sprangletop typically grow in moist soil areas. Once every five years, moist soil units undergo a removal of all vegetation and a re-working of the soil to improve aeration and fertility.
Riparian areas at the Refuge are filled with plants and trees that provide protective cover and nesting sites for many wildlife species. Willow and cottonwood trees provide shade and feeding areas for migrating birds, as well as year-round habitat for a host of aquatic animals. These areas play an important role in providing water to resident wildlife during the late spring and summer months.
Uplands are not irrigated and primarily get their water form rain. These areas include a wide variety of plant communities such as non-native annual grass and alkali playas with vernal pools scattered throughout. Management of these areas primarily consists of cattle grazing from November through April to help provide optimum habitat for blunt-nosed leopard lizards, Tipton kangaroo rat, and San Joaquin kit fox.
Salt Cedar is a deciduous shrub native to Southern Europe into Mongolia, Tibet, Central China, and North Korea. It was first introduced in the United States in the early 1800s and has since become a major problem in many arid areas of the arid regions of the southwest. Fortunately, this invasive species is seen on the Refuge as isolated plants or smaller stands. Control methods range from mechanical removal coupled with herbicide treatment and foliar herbicide treatments and a ninety percent eradication is feasible in the next 5 years.