DOI: 10.5061/dryad.k6djh9wdx
title: Fluxes and concentrations of dissolved organic carbon in soils

description: 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 (%),
 Alo+1/2Feo (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 yr-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)].
description: The data were compiled from data in our study and those from
 published sources by searching for “dissolved organic carbon”, “solute”,
 “flux”, “leaching”, and “soil” in Google Scholar. We compiled the data of
 DOC fluxes in throughfall and soil profiles from 91 sites, of which the
 DOC flux data at 18 sites have been published by our group. The climate
 was classified into four groups [polar climate (MAT &lt; 0 ºC), boreal
 climate (0 ºC &lt; MAT &lt; 6 ºC), temperate climate (6 ºC
 &lt; MAT &lt; 20 ºC), tropical climate (20 ºC &lt; MAT)],
 based on mean annual air temperature. The other
 parameters include climatic properties [mean annual precipitation and mean
 annual air temperature], plant litter properties [litterfall C input, C/N
 ratio, Klason-lignin (residue after digestion with sulfuric acid; Allen et
 al., 1974), lignin/N ratio, root litter production] and soil properties
 [soil C stocks (O horizon and mineral soil (0-30 cm depth)), pH (water
 extraction), clay content, short-range-order (amorphous) aluminum (Al),
 iron (Fe) (acid ammonium oxalate extractable Al and Fe; McKeague and Day,
 1966)]. The sampling and analytical methods are
 concisely summarized as follows: Throughfall (canopy leaching) samples
 were collected by precipitation collector, while soil solution samples
 were collected using tension-free lysimeters for downward flux of water
 percolating in the soil profiles. Sample solutions were filtered through a
 0.45 µm filter (e.g., PTFE syringe filter) and stored at 1°C in the dark
 prior to analyses. The concentrations of DOC were determined using a total
 organic carbon and nitrogen analyzer (TOC-V<sub>CSH</sub>,
 Shimadzu, Japan). The dissolved organic nitrogen (DON) concentrations were
 calculated by subtracting dissolved inorganic nitrogen (sum of
 NH<sub>4</sub><sup>+</sup> and
 NO<sub>3</sub><sup>-</sup>) from TDN
 concentrations (DON = TDN -
 NH<sub>4</sub><sup>+</sup> -
 NO<sub>3</sub><sup>-</sup>) to obtain DOC/DON
 ratios in soil solution. The DOC flux at the depth of 0 cm (the bottom of
 organic layers) and the bottom of B horizon (the bottom of rooting zone)
 was estimated by multiplying DOC concentrations in soil solution and water
 fluxes at each depth. Soil water fluxes were estimated by hydrological
 models or precipitation-evapotranspiration water budgets. Annual root
 production was measured by ingrowth core method, net sheet method, or
 sequential sampling method and estimated to be equal to annual root litter
 inputs. Proportion of DOC flux from the O horizon
 relative to C input via both throughfall and litterfall was calculated by
 dividing DOC flux from the O horizon by C input via both throughfall and
 litterfall. DOC retention in the mineral soil was calculated as the
 percentage of net decrease in DOC flux between O and B horizons relative
 to DOC flux from the O horizon. The apparent turnover time (yr) of soil C
 was estimated by dividing soil C stocks (Mg C ha<sup>–1</sup>)
 by C inputs (net DOC inputs and root litter inputs into the mineral soil)
 (Mg C ha<sup>–1</sup> yr<sup>–1</sup>).
description: # Fluxes and concentrations of dissolved organic carbon in soils This
 README file was generated on 2024-01-30 by Kazumichi Fujii. Site and soil
 information and fluxes and concentrations of dissolved organic carbon in
 soils # Principal Investigator Contact Information Name: Kazumichi Fujii
 Institution: Forestry and Forest Products Research Institute Address:
 Tsukuba 305-8687, Japan. Email: # Abstract
 To identify the factors regulating fluxes and concentrations of dissolved
 organic carbon (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 (%), Alo+1/2Feo (g kg-1), O horizon C stock
 (Mg C ha-1), Mineral soil C stock (Mg C ha-1)], fluxes and concentrations
 of DO C[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
 yr-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)]. ## Description of the data
 and file structure DATA-SPECIFIC INFORMATION FOR: Table_DOC.xlsx 1. Number
 of variables: 35 (Table S1) 2. Number of cases/rows: 92 3. Variable List:
 Table S1: *Country *Region or state *Coordinates *Vegetation *Mean annual
 air temperature (ºC) *Climate type *Vegetation type *Mycorrhiza type *Soil
 (USDA, Soil Taxonomy) *Litter pH (H2O) *Soil pH (H2O) *Soil C/N ratio
 *Clay (%) *Alo+1/2Feo (g kg-1) *O horizon C stock (Mg C ha-1) *Mineral
 soil C stock (Mg C ha-1) *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/DON (O horizon) *DOC/DON (B horizon) *Precipitation (mm yr-1)
 *Water flux at the bottom of the O horizon (mm yr-1) *Water flux at the
 bottom of B horizon (mm yr-1) *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) *DOC retention in mineral soil (%)
 *DOC flux relative to C input (%) *Contribution of DOC to C input in
 mineral soil (%) *Turnover time of mineral soil C (yr) 4. Missing data
 codes: NA (data not available) 5. Specialized formats or other
 abbreviations used: BOR, TEMP, and TROP represent boreal, temperate, and
 tropical climates, respectively. C, B, BF, and G represent coniferous
 forest, broad-leaved forest, leguminous broad-leaved forest, and
 grassland, respectively. AM, ECM, and ERM represent arbuscular mycorrhizal
 association, ectomycorrhizal association, and ericoid mycorrhizal
 association, respectively. ## Sharing/Access information
 Licenses/restrictions placed on the data: CC0 1.0 Universal (CC0 1.0)
 Public Domain Links to other publicly accessible locations of the data:
 None Data was derived from the following sources: 1. Fujii and Hayakawa
 (2022b) for DOC, Fujii and Hayakawa (2022a) for lignin 2. Peichl et al.
 (2007) with modification (DOC flux from the O horizon was calculated using
 throughfall water flux), Delaney et al. (1996), Nadelhoffer and Raich
 (1992) for FRP, Kothawala et al. (2009) for Al/Fe 3. Johnson et al. (2000)
 for DOC, Fahey et al. (2005) for LF, Currie and Aber (1997) for lignin,
 Bailey et al. (2003) for mean annual air temperature, Porras et al. (2017)
 for Al/Fe 4. McDowell and Liken (1988) for DOC, Fernandez et al. (2003)
 for soil pH, Currie and Aber (1997) for lignin 5. Yavitt and Fahey (1986)
 for DOC, Fahey et al. (1983) for LF, Mccahon and Munn (1991) for soil pH,
 Chatterjee et al. (2009) for soil C 6. Qualls et al. (1991; 2000) for DOC,
 Bonito et al. (2003) for soil pH, Currie et al. (1996) for lignin and LF
 C/N 7. Markewitz and Richter (1998) for DOC, Cybulski III et al. (2000)
 for lignin, Richter et al. (1999) for soil C 8. Dosskey and Bertsch (1997)
 for DOC, Megonigal et al. (1997) for LF, Currie et al. (1996) for lignin
 and LF C/N, McDowell and Liken (1988) for throughfall DOC concentration,
 Baker III et al. (2001) for FRP 9. Currie et al. (1996) for DOC, Magill et
 al. (2004) for LF, Aber et. (1995) for FRP, Porras et al. (2017) for Al/Fe
 10. Yano et al. (2004, 2005) for DOC, Valachovic et al. (2004) for lignin
 11. Sanderman and Amundson (2008), Valachovic et al. (2004) and Henry et
 al. (2008) for lignin 12. McDowell (1998) for DOC, Hall and Silver (2015)
 for clay content, Cuevas et al. (1991) for LF and FRP, Bloomfield et al.
 (1997) for lignin and C/N, Ostertag et al. (2003) for O horizon mass, Wang
 et al. (2002) for soil C 13. Schwendenmann and Veldcamp (2005) for DOC,
 Kleber et al. (2007) for soil pH, Raich et al. (2007) for lignin, Russell
 (2007) for FF, Valverde-Barrantes(2007) for FRP 14. Tobón et al. (2004a)
 for DOC, Tobón et al. (2004b) for TF, Jiménez et al. (2009) for FRP 15.
 McClain et al. (1997) for DOC, Cornu et al. (1997) for pH 16. Markewitz et
 al. (2004) for DOC, Silver et al. (2004) and Trumbore et al. (2006) for
 FRP, Joslin (2007) for lignin, Martinelli et al. (2007) for C/N, Quesada
 et al. (2020) for Al/Fe 17. Mulder et al. (1999) for DOC, Johansson (1995)
 for lignin, Leppälammi-Kujansuu et al. (2014) for FRP 18. Fröberg et al.
 (2005) for DOC, Kleja et al. (2008) for LF, Johansson (1995) for lignin,
 Leppälammi-Kujansuu et al. (2014) for FRP 19. Piirainen et al. (2002) for
 DOC, Johansson (1995) for lignin, Piirainen et al. (2015) for FF,
 Palviainen (2005) for soil C, Leppälammi-Kujansuu et al. (2014) for FRP
 20. Gundersen et al. (1998) for DOC, Emmett et al. (1995) for soil pH,
 Emmett et al. (1998) for TF, Prescott et al. (2000) for lignin, Alexander
 and Fairley(1983) for FRP 21. Schmidt et al. (2004) for DOC, Field et al.
 (2017) for LF, Beier et al. (2009) for subsoil DOC and FRP, Van Meeteren
 et al. (2007) for LF lignin and C/N 22. Gundersen et al. (1998) for DOC,
 Scarascia-Mugnozza et al. (2000) for FRP 23. Nielsen et al. (1999) for
 DOC, Pedersen and Bille-Hansen (1999) for LF, Jurkšienė et al. (2007) for
 LF lignin and C/N, Nielsen et al. (2000) for soil C and Al/Fe,
 Scarascia-Mugnozza et al. (2001) for FRP 24. Mossin et al. (2001) for DOC,
 Pedersen and Bille-Hansen (1999) for LF, Prescott et al. (2000) for
 lignin, Scarascia-Mugnozza et al. (2001) for FRP 25. Gundersen et al.
 (1998) for DOC, de Vries et al. (1995) for soil pH, Field et al. (2017)
 for LF, Beier et al. (2009) for FRP, Van Meeteren et al. (2007) for LF
 lignin and C/N 26. Gundersen et al. (1998) for DOC, Johansson (1995) and
 Prescott et al. (2000) for lignin 27. Guggenberger and Zech (1993) for
 DOC, Kalbitz et al. (2004) for LF and FF, Johansson (1995) for lignin,
 Wiesmeier et al. (2012) for SC, Scarascia-Mugnozza et al. (2000) for FRP
 28. Kalbitz et al. (2004) for DOC, Johansson (1995) for lignin 29.
 Michalzik and Matzner (1999), Johansson (1995) for lignin, Wiesmeier et
 al. (2012) for SC, Scarascia-Mugnozza et al. (2000) for FRP 30. Solinger
 et al. (2001) for DOC, Staaf (1987) for lignin, Wiesmeier et al. (2012)
 for SC, Scarascia-Mugnozza et al. (2004) for FRP 31. Don and Schulze
 (2008) for DOC, Bessler et al. (2009) for root:shoot allocation ratio,
 Henry et al. (2008) for lignin and C/N 32. Sleutel et al. (2009) for DOC,
 Van Den Berge et al. (2021) for soil C, Hansson et al. (2013) for FRP 33.
 Mulder et al. (2000) for DOC, Marcos and Lancho (2002) for soil pH,
 Gallardo et al. (2000) for Al/Fe, Gallardo and Merino (1992) for LF lignin
 and C/N 34. Prokushkin et al. (2008; 2011) for DOC, FF and soil pH,
 Kajimoto et al. (1999) for LF, Mikson and Roshchin (2021) for lignin,
 Usoltsev et al. (2022) for FRP 35. Prokushkin et al. (2005; 2006; 2011)
 for DOC, FF and soil pH, Kajimoto et al. (1999) for LF, Mikson and
 Roshchin (2020) for lignin, Usoltsev et al. (2022) for FRP 36. Fujii et
 al. (2008) 37. Fujii et al. (2021) 38. Fang et al. (2009) 39. Zhou et al.
 2016 for DOC, Zhang et al. 2013 for LF and FF, Barbhuiya et al. (2008) for
 lignin and C/N, Tang et al. (2012) for soil C, Bibi et al. (2022) for FRP,
 Kramer et al. (2017) for Al/Fe 40. Schmidt et al. (2010) for DOC, Liu and
 Chen(2004) for Al/Fe, Hishi and Takeda (2005) for FRP 41. Fujii et al.
 (2009a) 42. Fujii et al. (2017) 43. Fujii et al. (2009b) 44. Fujii et al.
 (2020a) 45. Fujii et al. (2011) for Doc, Fujii et al. (2020a) for FRP 46.
 Schrumpf et al. (2006) for DOC, Røhr (2003) for seepage water flux, Becker
 et al. (2015) for LF, Sierra Cornejo et al. (2020) for FRP, Gerschlauer et
 al. (2016) for soil C, Becker et al. (2015), Ostertag et al. (2008), and
 Bonanomi et al. (2021) for C/N and lignin 47. Versini et al. (2014) for
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