TY - JOUR
T1 - Soil dissolved organic carbon in terrestrial ecosystems
T2 - Global budget, spatial distribution and controls
AU - Guo, Ziyu
AU - Wang, Yihui
AU - Wan, Zhongmei
AU - Zuo, Yunjiang
AU - He, Liyuan
AU - Li, Dan
AU - Yuan, Fenghui
AU - Wang, Nannan
AU - Liu, Jianzhao
AU - Song, Yanyu
AU - Song, Changchun
AU - Xu, Xiaofeng
N1 - Publisher Copyright:
© 2020 John Wiley & Sons Ltd
PY - 2020/12
Y1 - 2020/12
N2 - Aims: Soil dissolved organic carbon (DOC) is a primary form of labile carbon in terrestrial ecosystems, and therefore plays a vital role in soil carbon cycling. This study aims to quantify the budgets of soil DOC at biome and global levels and to examine the variations in soil DOC and their environmental controls. Location: Global. Time period: 1981–2019. Methods: We compiled a global dataset and analysed the concentration and distribution of DOC across 10 biomes. Results: Large variations in DOC are found among biomes across space and the soil DOC concentration declines exponentially along soil depths. Tundra has the highest soil DOC concentration in 0–30 cm soils [453.75 (95% confidence interval: 324.95–633.5) mg/kg], whereas tropical and temperate forests have relatively lower DOC concentrations, ranging from 30.20 (24.78–36.80) to 54.54 (49.77–59.77) mg/kg. DOC generally accounts for < 1% of total organic carbon in soils, and DOC in 0–30 cm contributes more than half of the total DOC in the 0–100 cm soil profile. Furthermore, variations in DOC are primarily controlled by soil texture, moisture, and total organic carbon. Main conclusions: A global synthesis is combined with an empirical model to extrapolate the DOC concentration along soil profiles across the globe, and global budgets of DOC are estimated as 7.20 Pg C in the top 0–30 cm and 12.97 Pg C in the 0–100 cm soil profile, respectively, with a considerable variation among biomes. The strong soil texture control but weak total organic carbon (TOC) control on DOC variations suggest that the investigation of physical protection of soil organic carbon might need to expand to consider the labile C in soils. The global maps of DOC concentration serve as a benchmark for validating land surface models in estimating carbon storage in soils.
AB - Aims: Soil dissolved organic carbon (DOC) is a primary form of labile carbon in terrestrial ecosystems, and therefore plays a vital role in soil carbon cycling. This study aims to quantify the budgets of soil DOC at biome and global levels and to examine the variations in soil DOC and their environmental controls. Location: Global. Time period: 1981–2019. Methods: We compiled a global dataset and analysed the concentration and distribution of DOC across 10 biomes. Results: Large variations in DOC are found among biomes across space and the soil DOC concentration declines exponentially along soil depths. Tundra has the highest soil DOC concentration in 0–30 cm soils [453.75 (95% confidence interval: 324.95–633.5) mg/kg], whereas tropical and temperate forests have relatively lower DOC concentrations, ranging from 30.20 (24.78–36.80) to 54.54 (49.77–59.77) mg/kg. DOC generally accounts for < 1% of total organic carbon in soils, and DOC in 0–30 cm contributes more than half of the total DOC in the 0–100 cm soil profile. Furthermore, variations in DOC are primarily controlled by soil texture, moisture, and total organic carbon. Main conclusions: A global synthesis is combined with an empirical model to extrapolate the DOC concentration along soil profiles across the globe, and global budgets of DOC are estimated as 7.20 Pg C in the top 0–30 cm and 12.97 Pg C in the 0–100 cm soil profile, respectively, with a considerable variation among biomes. The strong soil texture control but weak total organic carbon (TOC) control on DOC variations suggest that the investigation of physical protection of soil organic carbon might need to expand to consider the labile C in soils. The global maps of DOC concentration serve as a benchmark for validating land surface models in estimating carbon storage in soils.
KW - biomes
KW - dissolved organic carbon
KW - terrestrial ecosystems
KW - vertical distribution
UR - http://www.scopus.com/inward/record.url?scp=85092371723&partnerID=8YFLogxK
U2 - 10.1111/geb.13186
DO - 10.1111/geb.13186
M3 - Article
AN - SCOPUS:85092371723
SN - 1466-822X
VL - 29
SP - 2159
EP - 2175
JO - Global Ecology and Biogeography
JF - Global Ecology and Biogeography
IS - 12
ER -