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Updated: Jun 5, 2025
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Combined Size and Density Fractionation of Soils for Investigations of Organo-Mineral Interactions
Published on: February 15, 2019
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Dominant Edaphic Controls on Particulate Organic Carbon in Global Soils.
Ziyu Guo1,2,3, Jianzhao Liu1,3, Liyuan He2
1State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin, China.
Global Change Biology
|December 11, 2024
Summary
Particulate organic carbon (POC) is vital for soil carbon storage and climate mitigation. This study maps global POC, revealing highest concentrations in boreal forests and identifying key factors influencing its distribution across biomes.
Area of Science:
- Soil Science
- Biogeochemistry
- Environmental Science
Background:
- Particulate organic carbon (POC) is a major soil organic carbon component crucial for global carbon mitigation.
- Understanding POC's spatial distribution and controls is essential for accurate soil carbon modeling.
Purpose of the Study:
- To investigate the spatial variation and controls of particulate organic carbon (POC) concentration globally.
- To develop a global map of soil POC density and estimate global POC stocks.
- To identify key factors influencing POC concentration across different biomes.
Main Methods:
- Compiled a global dataset of 3418 POC concentration data points.
- Applied empirical modeling and machine learning algorithms to analyze spatial variation and controls.
- Developed global maps of soil POC density for 0-30 cm and 0-100 cm soil profiles.
Main Results:
- Global topsoil (0-30 cm) POC concentration is estimated at 3.02 g C/kg dry soil, decreasing from poles to the equator.
- Boreal forests show the highest POC concentration (4.58 g C/kg), while savannas have the lowest (1.41 g C/kg).
- Global POC stocks are estimated at 158.15 Pg C (0-30 cm) and 222.75 Pg C (0-100 cm).
- Edaphic factors (bulk density, soil C content) are primary controls on POC concentration across biomes.
- Secondary controls vary by biome: climate in grasslands/shrublands, vegetation in forests.
Conclusions:
- The study provides benchmark estimates and maps of soil POC density, valuable for C fraction modeling.
- Incorporating biological and physiochemical mechanisms into soil C models is recommended to forecast POC dynamics under global change.
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