Soil organic carbon stocks in Alaska estimated with spatial and pedon data
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Resource Abstract:
Temperatures in high-latitude ecosystems are increasing faster than the average rate of global warming, which may lead to
a positive feedback for climate change by increasing the respiration rates of soil organic C. If a positive feedback is confirmed,
soil C will represent a source of greenhouse gases that is not currently considered in international protocols to regulate
C emissions. We present new estimates of the stocks of soil organic C in Alaska, calculated by linking spatial and field data
developed by the USDA NRCS. The spatial data are from the State Soil Geographic database (STATSGO), and the field and laboratory
data are from the National Soil Characterization Database, also known as the pedon database. The new estimates range from
32 to 53 Pg of soil organic C for Alaska, formed by linking the spatial and field data using the attributes of Soil Taxonomy.
For modelers, we recommend an estimation method based on taxonomic subgroups with interpolation fot missing areas, which yields
an estimate of 48 Pg. This is a substantial increase over a magnitude of 13 Pg estimated from only the STATSGO data as originally
distributed in 1994, but the increase reflects different estimation methods and is not a measure of the change in C on the
landscape. Pedon samples were collected between 1952 and 2002, so the results do not represent a single point in time. The
linked databases provide an improved basis for modeling the impacts of climare change on net ecosystem exchange. ?? Soil Science
Society of America. All rights reserved.
Citation
Title Soil organic carbon stocks in Alaska estimated with spatial and pedon data