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26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 26 GUIDE TO NEBRASKA'S WETLANDS CENTRAL TABLE PLAYAS Profi le Central Table Playa wetlands are situated on relatively fl at, loess soil tablelands surrounded by a landscape highly dissected by drainages. The largest cluster of wetlands is located near the town of Arnold in Custer County, but similar wetlands are scattered in some of the surrounding counties. A particularly large wetland basin located 11 miles east of Arnold has been the source of much speculation that its formation was caused by meteorite impact. However, investigations suggest it is of wind-formed origin, like other playa wetlands (Flowerday 2001). Central Table Playas receive water from runoff and are small (mostly less than 5 acres), temporarily and seasonally fl ooded wetlands. The complex may represent an extension of the Southwest Playas east toward the Rainwater Basin and Todd Valley complexes. The wetlands in this complex are possibly remnants of a larger area of wetlands that was naturally eroded, breached and drained by streams. It's unknown why this area has a more developed natural drainage pattern than the other complexes. Loss and Threats Based on hydric soil mapping units and depressional wetland points defi ned in the Soil Survey Geographic Database, as well as the palustrine wetlands delineated in the National Wetlands Inventory, it is estimated over 6,300 playas covered more than 18,000 acres (RWBJV 2013a). Based on an assessment of aerial photography completed in 2010, just over half of these playas, or 3,470 individual wetland footprints, continue to demonstrate some level of function, such as ponding water or growing hydric vegetation (Bishop et al. 2011). Some of the wetlands have been modifi ed by concentration pits or drained by ditches. In some locations, the hydrology of the watershed has been altered by the placement of terraces and diversions that reduce the amount of water entering the wetlands. Most of the Central Table Playas are farmed as conditions allow. Culturally accelerated sedimentation is an ongoing threat (LaGrange et al. 2011). Benefi ts Our understanding of the benefi ts of the Central Table Playa wetlands is limited by the lack of information, but they likely provide groundwater recharge and water quality improvement services. The wetlands are often visited by endangered whooping cranes during migration. These wetlands also provide habitat for migrating waterbirds, including waterfowl, shorebirds, and wading birds. The Central Table Playas are mostly within the Central Loess Hills Biologically Unique Landscape (Schneider et al. 2011). Conservation Success Stories A coordinating wildlife biologist, along with several partners, has worked in the area to quantify wildlife use of the playas. In addition, this biologist has helped develop conservation programs and make landowners aware of these opportunities. It has been challenging to fi nd the best program fi t, but several landowners are participating in USDA wetland conservation programs, and efforts continue to identify what Endangered whooping cranes use many Nebraska wetlands, including Central Table Playas, during their spring and fall migrations. ERIC FOWLER, NEBRASKALAND

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