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 Creating accurate soil maps at large scales using traditional methods is a timeconsuming and expensive process. However, remote-sensing techniques can provide spatially and spectrally contiguous data in a timely manner. For this study, 20 root zone soil moisture maps derived from Landsat images during the growing season were used for the detection of soil boundaries. A split moving-window analysis along two demonstration transects in, respectively, a semi-arid desert and riparian area located in the Middle Rio Grande Valley of New Mexico showed that remotely sensed root zone soil moisture can reveal subsurface trends that can be used to identify soil boundaries that do not have a strong surface expression. Overall, the use of multiple remotely sensed root zone soil moisture and Landsat images for soil boundary delineation shows great promise of becoming a valuable tool in the field of digital soil mapping.

Abstract Dryland channel networks share many similarities with channel networks in more humid regions, but they are also unique in having: extreme temporal and spatial variability in rainfall, runoff, and both hillslope and channel processes; poor integration between tributary and main channels; dominantly ephemeral or intermittent flow; and lack of equilibrium between process and form. Floods are likely to be particularly important in dryland channels, and riparian vegetation exerts a strong influence on channel processes and form. Land managers working in dryland channel networks particularly need to answer the following questions: What is stable? What is the role of disturbance? How do ecosystems depend on physical form and process? This paper explores methods for determining thresholds and resiliency within a channel network and suggests metrics that can be used to assess the condition of a channel segment or entire drainage network relative to management goals. The management metrics focus on flow regime, sediment supply, bed grain size, bedform configuration, width/depth ratio, bed gradient, channel planform, and extent and type of riparian vegetation. For each of these metrics, geological, historical, and systematic records can be used to define the natural range of variability for a particular channel form in the absence of direct land-use impacts. The range of variability present under land use such as military training activities can then be compared to the natural range to assess whether these activities are negatively affecting the dryland channel network. The Yuma Wash drainage in the Yuma Proving Ground, Arizona, is used as a case study.