Department of Earth Sciences - Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508TA Utrecht, the Netherlands
Abstract. Abstract. Dissolved carbon 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 vs. 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 and from 0.42 to 372.1 (median = 5.50) mg C/L for subsoils (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 (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 R2 = 0.45). Highest subsoil concentrations are calculated for Histosols.
This preprint has been withdrawn.
How to cite. Langeveld, J., Bouwman, A. F., van Hoek, W. J., Vilmin, L., Beusen, A. H. W., Mogollón, J. M., and Middelburg, J. J.: Global database and model on dissolved carbon in soil solution, Biogeosciences Discuss. [preprint], https://doi.org/10.5194/bg-2019-238, 2019.
Received: 13 Jun 2019 – Discussion started: 01 Jul 2019
We compiled a global database on annual average dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in soil solutions. We use this database to construct the first global models and maps on DOC in soil pore water. Highest concentrations in shallow soils occur in forests of cooler, humid zones. Highest concentrations in deeper soils are calculated for Histosols. Our research enables a spatially explicit first estimation of dissolved carbon in soil solution on the global scale.
We compiled a global database on annual average dissolved organic carbon (DOC) and dissolved...