Abstract
Tallgrass prairie once occupied 67.6 million hectares in the North American Midwest but less than 0.1% remains today. Consisting of more than 2200 ha, Neal Smith National Wildlife Refuge (NSNWR) was established by the US Fish and Wildlife Service in the 5217 ha Walnut Creek watershed in Jasper County, Iowa. Large tracts of land are being converted from row crop agriculture to native prairie and savanna with the goal to restore the landscape to a semblance of the condition that existed prior to Euro-American settlement. Understanding hydrologic processes at the watershed scale has been a focus of research at NSNWR for nearly two decades and the purpose of this paper is to integrate research results from monitoring projects to assess the progress made towards restoring five key hydrologic components: the water balance, stream network, streamflow hydrograph, groundwater levels and water quality. Restoration of hydrology is severely challenged by the history of hydrologic changes that occurred in the basin during a century of intensive agricultural activity. We document measurable progress in restoring key hydrologic processes in some areas, particularly in upland catchments compared to the larger watershed scale and discuss the timeframe needed to observe changes at short- and long-term scales.
Highlights
Introduction0.1% remain today [1]. In Iowa, the amount of remnant prairie left today is less than 11,300 ha, but less than 0.05% is of good quality [2]
Tallgrass prairie once occupied 67.6 million hectares in the North American Midwest but less than0.1% remain today [1]
Two decades of hydrologic research at the Neal Smith National Wildlife Refuge (NSNWR) in the Walnut Creek watershed has led to new insights on the relation of hydrology to ecological restoration
Summary
0.1% remain today [1]. In Iowa, the amount of remnant prairie left today is less than 11,300 ha, but less than 0.05% is of good quality [2]. In the Walnut Creek watershed, hydrologic processes, such as precipitation, discharge, groundwater flow and water quality, are dominating forces in the basin, making the ecosystem- or landscape-level approach the appropriate scale for restoration. The Walnut Creek Watershed Monitoring Project was a 10-year project (1995–2005) designed to evaluate changes in hydrology and water quality resulting from land cover conversion from row crop to native prairie at the refuge [9]. Integrating research results from the many smaller, focused studies within the larger watershed context are an opportunity to evaluate the potential for restoration of key hydrologic processes at a landscape scale. Our goal is to reconcile the restoration potential of NSNWR against the original landscape condition and the historical impacts of agricultural intensification to address the following questions: what aspects of hydrology and water quality are restorable, at what locations are they best addressed, and under what timeframe will improvements be seen?
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
