Digital soil mapping to support California ecological site development

Authors: Salley, Shawn

Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: 2/28/2020
Publication Date: 2/29/2020
Citation: Salley, S.W. 2020. Digital soil mapping to support California ecological site development. National Cooperative Soil Survey Newsletter. 90:27-28.

Interpretive Summary:

Technical Abstract: In late January 2020, soil and rangeland scientists from the Agricultural Research Service (ARS) joined conservation staff from the Santa Lucia Conservancy in Carmel, California, to describe and sample grassland soils of the Central California Coastal Range. Recently, ARS scientists entered into a partnership with the Santa Lucia Conservancy, which stewards an 18,000-acre preserve of protected natural lands, to provide expertise and advice on rangeland ecology, develop state-and transition models, and analyze grazing and landscape data to evaluate grassland and rangeland response to the conservancy’s targeted grazing program. ARS cooperators used digital soil mapping techniques to sample and map soils classes across the preserve’s grasslands. Prior to sampling, we applied the conditioned Latin Hypercube Sampling (cLHS) method, a random stratified procedure that chooses sampling locations based on a suite of soil-forming environmental variables. Using cLHS with a sampling number optimization algorithm and a cost constrained implementation, we identified 41 soil and vegetation sampling sites across the preserve’s coastal prairie and oak savanna landscapes. Many stakeholders and cooperators joined the soil and vegetation field sampling, including scientists from NRCS (Genevieve Landucci, Templeton, California), Point Blue Conservation Science (Chelsea Carey, Petaluma, California), the California Conservation Corps, Americorps Watershed Stewards Program, and the Santa Lucia Conservancy. The next step is to analyze chemical and physical properties of the soil samples and conduct analysis of the conservancy’s vegetation and grazing data. Our collaboration helps support the Santa Lucia Conservancy’s science-based mission to enable data-driven assessments of grassland and rangeland conditions, including the development of best management practices that promote native herbaceous plants, reduce noxious weeds, control non-native vegetation, and prevent brush encroachment.