The Playa Lakes Joint Venture (PLJV) works in the short- and mixed-grass Bird Conservation Regions 18 and 19, which include portions of Colorado, Kansas, Nebraska, New Mexico, Oklahoma, and Texas. This region is dominated by agricultural land uses such as crop cultivation and livestock grazing with over half of the area in cropland.
Grasslands are the dominant habitat in the PLJV landscape. Short grass prairie primarily consists of low-growing, warm-season grasses such as blue grama and buffalo grass. Sandsage prairie is found where sandy soils occur, and consists primarily of sandsage, sand bluestem and prairie sand-reed grasses. Mixed-grass such as needle-and-thread and side-oats grama, and some tall grasses such as big bluestem, little bluestem and switchgrass become more dominant further east. Prairies in the PLJV region support more than 400 species of birds and other wildlife. However, prairies are one of the most threatened ecosystems in North America and subsequently, prairie bird populations are experiencing some of the most significant population declines.
Although grasslands and shrublands are the primary native habitats in the region there are a variety of other water-associated habitats including playas, rivers and streams, wet meadows, and saline lakes. These habitats are vitally important to prairie birds, migrating waterfowl, and breeding and migrating shorebirds in this semi-arid landscape.
Playas — shallow, temporary wetlands that lie in the lowest point of a closed watershed — are the most numerous wetlands in the PLJV region, with more than 80,000 of them scattered across the western Great Plains. Their basins are lined with clay soil, which collect and hold water from rainfall and runoff events, creating temporary lakes. Playas are the center of biodiversity on the plains — supporting more than 200 species of birds and other wildlife. In this prairie landscape, these shallow wetlands are the main source of water, providing much needed rest stops and food to migrating waterfowl and shorebirds, as well as resident prairie birds. They are also the primary source of recharge for the High Plains (Ogallala) Aquifer, a 174,000 square mile groundwater formation that supplies the majority of the water needs in the western Great Plains. However, because of agricultural and other land conversion activities that result in sedimentation of the playas and loss of function, playas are critically threatened, with more than 70 percent of these wetlands now altered from their natural state.
Major rivers in the PLJV region include the Arkansas, Canadian, North and South Platte, Red and Republican. These rivers provide habitat for a variety of migratory birds, including species of conservation concern such as the Whooping Crane, Least Tern and Piping Plover. In the southern portion of the PLJV, many river and stream (riparian) areas go through wet-dry cycles, receiving brief surges of water only after heavy rains. Major threats to riparian areas are loss or change of water periods, fragmentation due to developments like diversions, dams and roads, invasion of exotic species like salt cedar and Russian olive, and lack of cottonwood regeneration. Efforts to restore riparian systems often include invasive species removal, replanting of native vegetative cover, and if on rangeland, fencing off river banks and installing alternative watering sources for livestock.
There are about 100 saline lakes located in the southern portions of the PLJV. They are closed systems which are fed by freshwater springs, several exceeding 1,000 acres. Saline lakes are generally ice-free in the winter and host large concentrations of migratory birds, especially when other sources of water are frozen. Saline lakes are important breeding sites for Snowy Plovers and roost sites for Sandhill Cranes and support large numbers during migration and winter.
Notable wetlands that have been protected through the North American Wetlands Conservation Act include Cheyenne Bottoms, Jamestown, and McPherson Valley Wetlands in Kansas and Hackberry Flat in Oklahoma. Other wetlands, such as Salt Plains in Oklahoma and Quivira in Kansas, are protected as National Wildlife Refuges. These sites, along with playas further west, are vitally important to the continental populations of migrating waterfowl and migratory shorebirds.