Vegetation and Topographic Control on Spatial Variability of Soil Organic Carbon

Soil organic carbon (SOC) is one of the most important parameters affecting the hydraulic characteristics of natural soils. Despite being rather easy to measure, SOC is known to be highly variable in space. In this study, vegetation, climate, and morphology factors were used to reproduce the spatial distribution of SOC in the mineral horizons of forest and grassland areas in north-western Italy and the feasibility of the approach was evaluated. When the overall sample (114 samples) was analyzed, average annual rainfall and elevation were significant descriptors of the SOC variability. However, a large part of the variability remains unexplained. Two stratification criteria were then adopted, based on vegetation and topographic properties. We obtained an improvement of the quality of the estimates, particularly for grasslands and forests in the absence of local curvatures. These results indicate that the spatial variability of soil organic matter is scarcely reproducible at the regional scale, unless an a-priori reduction of the heterogeneity is applied. A discussion on the feasibility of applying stratification criteria to deal with heterogeneous samples closes the pape

Water and People at the Confluence

Kentucky’s waterways carry a history of the landscape as well as life-sustaining water. Watersheds are any area of land draining water to a common water body, and the quality of the water body reflects human activity and natural processes. The Cane Run watershed is a polluted watershed in central Kentucky. A watershed-based plan was created by investigating the current status of the watershed and making plans to improve its conditions. Some progress has been made to improve the Cane Run watershed. Effective watershed-based plans require scientific inquiry as well as social considerations of the citizens in the watershed.</p