5. Discussion
The sites selected for soil sampling represent a geographic range of elevation, climate, and lithology for the western United States. The values of floodplain SOC at these degraded, treatment, and reference sites fall within the most common range (100-1000 Mg C/ha; Sutfin et al., 2016) of published values for floodplain SOC in temperate-latitude rivers. Our primary objective was to determine whether there are detectable differences in floodplain carbon stock between the categorized floodplain states of degraded, treatment, and reference, and to assess the carbon sequestration potential of stream restoration within the context of these simple categories. A secondary objective was to examine factors that influence floodplain SOC stock at a larger, regional scale across the western United States.