rapid carbon assessment of the u.s.: project overview and summary
TRANSCRIPT
Rapid Carbon Assessment of US
Rapid Carbon Assessment of the U.S. : Project Overview and SummarySkye WillsTerry Loecke, Stephen Roecker,Zamir Libohova, and Soil Survey Staff
March 21 – 23, 2017Presentation for the Global Soil Partnership, Global Symposium on Soil Organic Carbon
Rapid Carbon Assessment of US
Objective: Base-line inventory of soil carbon stocks for conterminous U.S.Evaluate impact of ecosystems, land use and cover
Rapid Carbon Assessment of US
Multi-stage Stratified Random Sampling► Not enough resources to sample all soil series► Target sampling
► Stratified Random Sampling– 17 regions
• (conterminous U.S.)► Within region Stratification
► 8 – 20 groups of soil series*► 6 LULC
► 5 types of Land use / cover (LULC): Cropland, Pastureland, Rangeland, Forest land, Wetland
*Wills et al., 2013
Rapid Carbon Assessment of US
RaCA Data CollectedInformation collected on
– 6,147 sites– 32, 053 pedons– 144,833 samples
Rapid Carbon Assessment of US
RaCA Data CollectedSite Information: landscape, vegetation, managementPedon Description and sample collection
– 5 pedons described– Samples collected by horizon to 1m– Bulk density samples collected to 50cm
Lab Analysis– All pedons
• Bulk Density*• Visible – Near Infrared Spectra
– Central pedon (1 per site)• Combustion – total carbon• Calcimeter – inorganic carbon
*Sequiera et al., 2014
Rapid Carbon Assessment of US
% SOC by Depth Bulk Density (g cm-3)
Rapid Carbon Assessment of US
Summaries
Rapid Carbon Assessment of US
Land Use – Land Cover SOC stocks stacked by depth increment
Rapid Carbon Assessment of US
Area Weighted - Land Use – Land Cover SOC stocks stacked by depth increment
Rapid Carbon Assessment of US
Rapid Carbon Assessment of US
Rapid Carbon Assessment of US
Preliminary Stocks (1 m)
Rapid Carbon Assessment of US
Conclusions• RaCA collected 6,000 pedons across the conterminous
United States• SOC stocks are skewed with a few very high values• Most SOC occurs within 5 – 30cm• Wetlands have the highest typical SOC stocks and
Rangelands have the lowest• A satisfactory map was made across the conterminous
US
Rapid Carbon Assessment of US
Questions?
Rapid Carbon Assessment of US
References– Wills, S., Seybold, C., Chiaretti, J., Sequeira, C., & West, L. (2013).
Quantifying tacit knowledge about soil organic carbon stocks using soil taxa and official soil series descriptions. Soil Science Society of America Journal, 77(5), 1711-1723.
– Sequeira, C. H., Wills, S. A., Seybold, C. A., & West, L. T. (2014). Predicting soil bulk density for incomplete databases. Geoderma, 213, 64-73.
– Soil Survey Staff and T. Loecke. 2016. Rapid Carbon Assessment: Methodology, Sampling, and Summary. S. Wills (ed.). U.S. Department of Agriculture, Natural Resources Conservation Service.
– Kern, J. S. (1994). Spatial patterns of soil organic carbon in the contiguous United States. Soil Science Society of America Journal, 58(2), 439-455.
– Guo, Y., Amundson, R., Gong, P., & Yu, Q. (2006). Quantity and spatial variability of soil carbon in the conterminous United States. Soil Science Society of America Journal, 70(2), 590-600.
Rapid Carbon Assessment of US
Data AvailabilitySearch engine: RaCA soilAll methodology and data (including R scripts used to make these figures)https://go.usa.gov/xXCjD
– Full url: https://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/survey/?cid=nrcs142p2_054164#methodology
R package: soilDB– fetchraca()
https://go.usa.gov/xXCjD
Rapid Carbon Assessment of US
Example slides to follow…………
Rapid Carbon Assessment of US
Rapid Carbon Assessment of US
Rapid Carbon Assessment of US