Land Use Policy 42 (2015) 426–431 Contents lists available at ScienceDirect Land Use Policy jo ur nal ho me pag e: www.elsevier.com/locate/landusepol Land use effects on sedimentation and water storage volume in playas of the rainwater basin of Nebraska Dale W. Daniel ∗ , Loren M. Smith, Scott T. McMurry Department of Zoology, Oklahoma State University, Stillwater, OK 74078, USA a r t i c l e i n f o Article history: Received 27 May 2014 Received in revised form 11 August 2014 Accepted 17 August 2014 Keywords: Cropland Ecosystem services Playa wetlands Sedimentation Wetlands Reserve Program (WRP) a b s t r a c t A region dominated by cropland, the Rainwater Basin (RWB) of Nebraska, contains playa wetlands of international importance but estimates of historic wetland numbers suggest that approximately 90% of wetlands have been lost through draining and filling. To reverse these losses and restore their ecosystem services, >2000 ha of wetlands in the RWB have been enrolled into the US Department of Agriculture (USDA) Wetlands Reserve Program (WRP). Our goal was to compare water storage volume and sediment loads in RWB playas in surrounding cropland, reference condition, and restored (WRP) land uses. To do so, we measured characteristics of 48 playas that dictate water storage capabilities essential to their service provisioning (historic/current playa area, playa volume, and sediment depth to clay pan). Using historic wetland hydric soil footprints, we determined loss of historic area for wetlands in each land use type and using soil cores we estimated sediment depth and volume loss. Reference condition playas had 380% more functional wetland area and 8 times more volume than cropland playas, WRP playas were intermediate between reference and cropland playas. In addition, reference condition playas had lost the least amount of historic area (65%) followed by WRP (70%) and cropland (83%). Though cropland playas lost the greatest extent of historic wetland area, they had sediment depths (to Bt layer) similar to playas embedded in reference and WRP, indicating that all playas in the region have been impacted by watershed soil erosion. In order to increase the overall positive impact on wetland services provided by enrolling playas into the WRP, conservation practitioners should remove sediments down to the Bt layer in enrolled wetlands in the RWB and protect the immediate watershed to prevent further erosion. © 2014 Elsevier Ltd. All rights reserved. Introduction Soil erosion due to watershed cultivation is a threat to wet- land services worldwide (Martin and Hartman, 1987; Luo et al., 1997; Craft and Casey, 2000; Junk et al., 2013; Daniel et al., 2014). Because depressional wetlands are the terminus in closed water- sheds, increased sediment accumulation in depressional wetland basins can reduce wetland volume and hydroperiod (Luo et al., 1997; Tsai et al., 2007), subsequently reducing their value as biotic habitat (Smith et al., 2011). Also, incoming sediments can cover native egg and seed banks, effectively altering community structure (Jurik et al., 1994; Euliss and Mushet, 1999; Gleason et al., 2003). In addition, excessive nutrient and contaminant inputs into wet- lands can coincide with upland erosion, especially from croplands, which favor the establishment of more competitive invasive plant ∗ Corresponding author at: Department of Zoology, Oklahoma State University, 501 Life Sciences West, Stillwater, OK 74078, USA. Tel.: +1 405 744 5555; fax: +1 405 744 7824. E-mail address: dale.daniel@okstate.edu (D.W. Daniel). species within the basin (Suding et al., 2005) and pollute wetlands and potentially groundwater (Belden et al., 2012). Rates at which eroded watershed soils are deposited into wetlands depend on factors including precipitation, soil type, topography, and land use (Wischmeier and Smith, 1978). In the semi-arid Southern High Plains (SHP) of Texas, sediment accumula- tion rates of playa wetlands, predominately embedded in cropland watersheds with >2% slopes, were greater than rates reported for any other wetland system (Luo et al., 1997). Intense cultivation has resulted in the loss or degradation of approximately 95% of playas in the SHP (Johnson et al., 2012). Furthermore, cropland playas throughout the entire western High Plains had on average lost their entire historic water storage capacity due to watershed soil erosion (Daniel et al., 2014). For comparison, estimated loss of wetlands in the glaciated Great Plains (Prairie Pothole region, PPR) due to agricultural practices exceeds 50% (Dahl, 1991). Rates of sed- iment accumulation for cultivated wetlands in the PPR were found to average 80 mg/cm/yr (Martin and Hartman, 1987). Cropland agriculture in the Rainwater Basin region (RWB) of Nebraska began approximately 50 years prior to widespread farm- ing of the SHP and has served as one of the most productive cropland http://dx.doi.org/10.1016/j.landusepol.2014.08.013 0264-8377/© 2014 Elsevier Ltd. All rights reserved.