Estimating dissolved carbon concentrations in global soils: a global database and model

SN Applied Sciences, vol. 2

Abstract

Abstract Dissolved carbon (C) leaching in and from soils plays an important role in C transport along the terrestrial-aquatic continuum. However, a global overview and analysis of dissolved carbon in soil solutions, covering a wide range of vegetation types and climates, is lacking. We compiled a global database on annual average dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in soil solutions, including potential governing factors, with 762 entries from 351 different sites covering a range of climate zones, land cover types and soil classes. Using this database we develop regression models to calculate topsoil concentrations, and concentrations versus depth in the subsoil at the global scale. For DIC, the lack of a proportional globally distributed cover inhibits analysis on a global scale. For DOC, annual average concentrations range from 1.7 to 88.3 (median = 25.27) mg C/L for topsoils (n = 255) and from 0.42 to 372.1 (median = 5.50) mg C/L for subsoils (n = 285, excluding lab incubations). Highest topsoil values occur in forests of cooler, humid zones. In topsoils, multiple regression showed that precipitation is the most significant factor. Our global topsoil DOC model ( $${\mathrm{R}}^{2}=0.36$$ R2=0.36 ) uses precipitation, soil class, climate zone and land cover type as model factors. Our global subsoil model describes DOC concentrations vs. depth for different USDA soil classes (overall ( $${\mathrm{R}}^{2}=0.45$$ R2=0.45 ). Highest subsoil DOC concentrations are calculated for Histosols.

Authors 7

1. Joep J. Langeveld corresponding

   Netherlands Environmental Assessment Agency · Utrecht University

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH, The Hague, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands

2. Lex Bouwman

   Netherlands Environmental Assessment Agency · Utrecht University · Ocean University of China

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, People’s Republic of China

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH, The Hague, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

   Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, People’s Republic of China

   PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands

3. Wim Joost van Hoek

   Utrecht University

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

4. Lauriane Vilmin

   Utrecht University · Deltares

   Affiliation as printed

   Deltares Delft, P.O. Box 177, 2600 MH, Delft, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   Deltares Delft, Delft, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

5. Arthur H. W. Beusen

   Netherlands Environmental Assessment Agency · Utrecht University

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH, The Hague, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands

6. José Manuel Mogollón Aachen Department of Industrial Ecology

   Leiden University · Utrecht University

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   Department of Industrial Ecology, Leiden University, P.O. Box 9518, 2300 RA, Leiden, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands

   Department of Industrial Ecology, Leiden University, Leiden, The Netherlands

7. Jack J. Middelburg

   Utrecht University

   Affiliation as printed

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA, Utrecht, The Netherlands

   Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands