Serpentinitic Problematic Hydric Soil in a Mediterranean Climate Along the Central Coast of California.

Wetlands are unique and sensitive environments important for ensuring water quality and encouraging species diversity. In order to protect wetlands, it is important to use proven scientific methods to delineate these habitats from seemingly similar uplands. A groundwater seep was chosen as a project site in Poly Canyon in San Luis Obispo, California for field and laboratory analyses. The soil has wetland hydrology with seasonal prolonged saturation and hydric vegetation.  However, the soil does not meet a meet a visual field indicator for hydric soils.  Therefore, the purpose of the study is to determine if this problematic soil site is a wetland.  Soil pH, temperature, and volumetric water content were measured at 10-cm increments to a depth of 50 cm. These data were collected weekly from January through June of 2013. Concurrently, a set of 5 Indicator of Reduction in Soil (IRIS) tubes were installed and removed biweekly at each site. The IRIS tubes were visually analyzed to determine amount of iron removed from the tube surface. IRIS tubes are an effective tool for identifying and delineating wetlands based on iron reduction. The results of the field and laboratory analysis will verify if the project site is a wetland and aid in the determination of a new visual field indicator for hydric soils.