Fluxes and concentrations of dissolved organic carbon in soils

<p>Dissolved organic carbon (DOC) in soil solution plays roles in soil C storage and biogeochemical cycles. Factors regulating fluxes and concentrations of DOC still remain unclear. To identify the factors regulating fluxes and concentrations of DOC in the soil profiles, we compiled the data of site information [Country, Region or state, Coordinates, Vegetation, Mean annual air temperature (ºC), Climate type, Vegetation type, Mycorrhiza type, Soil (USDA, Soil Taxonomy)], soil properties [Litter pH (H₂O), Soil pH (H₂O), Soil C/N ratio, Clay (%), Al_o+1/2Fe_o (g kg^-1), O horizon C stock (Mg C ha^-1), Mineral soil C stock (Mg C ha^-1)], fluxes and concentrations of DOC [Throughfall DOC flux (kg C ha^-1 yr^-1), DOC flux at the bottom of the O horizon (kg C ha^-1 yr^-1), DOC flux at the bottom of the B horizon (kg C ha^-1 yr^-1), DOC concentration at the bottom of the O horizon (mg C L^-1), DOC concentration at the bottom of the B horizon (mg C L^-1), DOC/Dissolved organic N (DON) (O horizon), DOC/DON (B horizon), Precipitation (mm yr^-1), Water flux at the bottom of the O horizon (mm y^r-1), Water flux at the bottom of B horizon (mm yr^-1)], plant litter properties [Litterfall C input (Mg C ha^-1 yr^-1), C/N ratio in litter, Lignin content in litter (%), Lignin/N ratio in litter, Root litter C input (Mg C ha^-1 yr^-1)], and DOC retention in mineral soil (%), DOC flux relative to C input (%), Contribution of DOC to C input in mineral soil (%), and Turnover time of mineral soil C (yr)].</p>