A systems-based approach to ecosystem services valuation of various atmospheric calcium deposition flows

Abstract

Atmospheric resources are very important for assessing ecosystem services at different administrative levels (e.g., state, region, etc.). Quantification of atmospheric calcium (Ca2+) deposition on the total basis provides incomplete information about the ecosystem services flows (both "natural" and "human-derived"), therefore lacking a systems approach to guide sustainable management of the flows which support many ecosystem services. This study assessed the value of wet, dry, and total atmospheric calcium deposition flows in the contiguous United States (U.S.) by different spatial aggregation levels (e.g., state, region) using information from the National Atmospheric Deposition Program (NRSP-3) and commodity prices of human-derived materials: agricultural limestone (CaCO3) and uncalcined gypsum (CaSO4•2H2O). The total provisioning ecosystem value of atmospheric calcium deposition flows was $66.7M (i.e., 66.7 million U.S. dollars) ($30M wet + $36.7M dry) based on an average 2014 price of $10.42 per U.S. ton of agricultural limestone (CaCO3) or nearly $364M ($164M wet + $200M dry) based on an average 2014 price of $33.00 per U.S. ton gypsum (CaSO4•2H2O). The quantified spatial distribution of wet, dry, and total atmospheric calcium deposition could be used to identify areas with opportunities for more efficient use of "human-derived" materials since they are already being supplied by atmospheric deposition.