ABSTRACT Streams in the Midwest of the United States have experienced major changes in their watersheds since European settlement that have altered sediment loads, runoff, nutrient concentrations, and the abundance of woody debris. Moreover, the near extirpation of keystone species such as beaver, and the construction of dams and impoundments (e.g., milldams, causeways, reservoirs, small ponds, etc.), have had impacts on the entrainment of sediments, the connectivity between tributaries, main channels, and floodplains, and channel form. As stream restoration efforts increase, how do we restore streams to their ‘natural’ state? Can streams restored to a pre–European settlement condition maintain equilibrium under current land use? Here we examine the impact of post-European settlement changes to a small (432 km 2 ) watershed in southwestern Ohio that is largely representative of rural watersheds in the Midwest. We examine the impact of nineteenth-century milldams, report the results of a 21-year study of nutrient and sediment concentrations in the upper portion of the watershed during a shift from conventional to conservation tillage, and assess the potential impact of the return of beavers on stream sediment and nutrient concentrations. Our objective is to understand how streams have been impacted by humans over the past 250 years, and to identify strategies for ‘restoring’ streams in the Midwest.

ABSTRACT The Sidney Geosol in Ohio and Indiana is believed to have developed between marine isotope stage (MIS) 5 and MIS 2. Development stopped when the Laurentide ice sheet extended south of the Great Lakes during MIS 2. Prior reported data and new chronological information are employed here to show that pedogenesis of the Sydney Geosol started prior to 50 cal ka and ended time-transgressively through burial by sediment of the Laurentide ice sheet. Near Sidney, Ohio, the termination age is ca. 25.9 cal ka, whereas at Snyder, Indiana, near the limit of the ice-sheet expansion, the age is ca. 21.9 cal ka. However, at Oxford, Ohio, an interstadial organic accumulation between till units may imply that the upper portion of the Sidney Geosol formed under different conditions than the remainder. At a third site, Huffman Park, Ohio, glacially transported tree remains represent a landscape older than 50 cal ka, which is currently difficult to correlate with any specific paleosol, but which suggests that further insights about conditions prior to ca. 25.9 cal ka may be preserved in the record.

Unlike other informal sites, fossil parks provide visitors collecting opportunities that result in ownership of a small number of fossils. In 2003, we investigated the first three identified U.S. fossil parks at Hamburg, New York; Sylvania, Ohio; and Rockford, Iowa. Case study analyses determined the opportunities to learn geobiology at each site. Data collection proceeded through lived learning experiences, and included field notes, photographic records, informal conversations with park participants, brochures, and on-site signage. Through constant comparative methods, six variable categories converged for fossil park development: (1) informative previsit Web site, (2) authentic collecting in situ, (3) authentic collecting tools, (4) accessibility, (5) fossil identification, and (6) visitor education. These variables were optimized in a model of fossil park design. In 2005, fossil parks at Sharonville, Ohio, and Fossil, Oregon, were investigated in phase 2 of our study, and in 2006, our third case study researched fossil parks in Aurora, North Carolina, and Republic, Washington. Analysis of the seven U.S. fossil park data sets resulted in the emergence of key variables that affected the visitors' opportunities to learn geobiology concepts at fossil parks: (1) authenticity of experience, (2) age of fossils, (3) fossil-collection training and facilities, (4) availability of on-site paleontological mentors, (5) fossil identification via signage and brochures, (6) site organization and wayfinding signs, and (7) accessibility of site, including safety. The seven U.S. fossil parks were ranked against these variables according to their effectiveness as informal science education sites. We conclude that fossil parks can provide valuable informal geobiology education that can contribute to the public's geobiological literacy.