Accounting for soil inorganic carbon in the ecosystem services framework for United Nations sustainable development goals

Soil inorganic carbon (SIC) is currently not included in the list of key soil properties related to ecosystem services (e.g., provisioning, regulating, cultural, and supporting services). Soil inorganic carbon is a dynamic key soil property used in soil classification, taxonomy and fertility, therefore its inclusion in the framework of ecosystem services is important. With soils rapidly changing due to human use and climate change, the ecosystem services framework should include not only soil organic carbon (SOC), but SIC as well since it is of global importance to soil fertility and the long-term carbon (C) cycle, especially in semiarid and arid climates where SIC comprises the largest C pool. The objective of this study is to assess the value of SIC in the 12 soil orders of Soil Taxonomy at the country scale (continental United States (U.S.)) and at the farm scale (the Cornell University Research Farm) within the context of ecosystem services, specifically provisioning and supporting services. At the country scale, the total estimated midpoint value of SIC storage within the upper two meters of soil is $5.17 T (i.e., 5.17 trillion U.S. dollars). The soil orders having the highest total value of SIC storage (based on an average 2014 price of $10.42 per U.S. ton of CaCO3 lime in the U.S.) are: 1) Mollisols ($2.22 T), 2) Aridisols ($1.23 T), 3) Alfisols ($523B, i.e., 523 billion U.S. dollars), and 4) Entisols ($489B). In terms of SIC content (i.e., value per square meter), the soil orders are ranked: 1) Vertisols ($2.22 m−2), 2) Aridisols ($1.52 m−2), 3) Mollisols ($1.10 m−2), and 4) Inceptisols ($0.49 m−2). At the farm scale, based on variable measured and reported soil sample depths, the soil orders having the highest total value of SIC (based on an average 2014 price of $10.88 price per U.S. ton of CaCO3 for the State of New York (NY)) were: 1) Alfisols, 2) Inceptisols, and 3) Entisols. However, the farm-scale estimates varied greatly depending on whether the values were based on field-derived vs. SSURGO-derived data. The results of this study begin to provide an estimated value of the importance of SIC when assessing ecosystem services. The potential impacts on society from this research include adding SIC into the ecosystem services framework for the United Nations (UN) Sustainable Development Goals. Future research should identify and quantify other important ecosystem services that SIC may provide on a variety of spatial and temporal scales, as well as the potential need of including total C (TC) and interactions between SIC and SOC pools.