Global patterns and drivers of soil dissolved organic carbon concentrations

<p>Dissolved organic carbon (DOC) constitutes the most active carbon pool in soils and plays critical roles in soil carbon cycling, plant productivity, and global climate change. Accurately assessing soil DOC quantity is essential to elucidate ecosystem functions and services. However, global...

Full description

Saved in:
Bibliographic Details
Main Authors: T. Ren, A. Cai
Format: Article
Language:English
Published: Copernicus Publications 2025-06-01
Series:Earth System Science Data
Online Access:https://essd.copernicus.org/articles/17/2873/2025/essd-17-2873-2025.pdf
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849423813907841024
author T. Ren
T. Ren
A. Cai
author_facet T. Ren
T. Ren
A. Cai
author_sort T. Ren
collection DOAJ
description <p>Dissolved organic carbon (DOC) constitutes the most active carbon pool in soils and plays critical roles in soil carbon cycling, plant productivity, and global climate change. Accurately assessing soil DOC quantity is essential to elucidate ecosystem functions and services. However, global driving factors and the spatial distribution of soil DOC remain poorly quantified, largely due to limited large-scale data. Here, we compile a comprehensive global database of soil DOC concentrations, encompassing 12 807 observations extracted from 975 scientific publications published between 1984 and 2020. We also record detailed geographic locations, climatic variables, and soil properties as predictors. Machine learning techniques were employed, including 10-fold cross-validation and evaluating model performance by <span class="inline-formula"><i>R</i><sup>2</sup></span> and root mean square error values, to predict the relative importance of various predictors and the global distribution of soil DOC concentrations. Worldwide soil DOC concentrations ranged from 0.04 to 7859 mg kg<span class="inline-formula"><sup>−1</sup></span>, averaging 222.78 mg kg<span class="inline-formula"><sup>−1</sup></span>. The 14 selected predictors, including elevation, soil properties, and climate, explained 63 % of the variance in soil DOC concentrations. Elevation played the most important predictor for soil DOC prediction, followed by soil organic carbon, seasonal variability of temperature, and soil clay content. Soil DOC decreases initially but increases when soil clay content exceeds 20 % and seasonal variability of temperature exceeds 0.7. Using these findings, a global map of predicted soil DOC concentrations was produced at a 0.05° by 0.05° resolution. Global soil DOC concentrations generally increased from the Equator to the poles wherein the topsoil layer (0–30 cm) holds 13.47 Pg of soil DOC with substantial variations across continents. These results inform soil management practices strategies, ecosystem services evaluations, and climate change mitigation efforts. Furthermore, we envision integrating our database with other carbon pools to advance understanding of total soil carbon turnover and to refine Earth system models. The dataset is publicly available at <a href="https://doi.org/10.6084/m9.figshare.28574183">https://doi.org/10.6084/m9.figshare.28574183</a> (Ren and Cai, 2025).</p>
format Article
id doaj-art-4cdab28e02f54420802b5887d607e16c
institution Kabale University
issn 1866-3508
1866-3516
language English
publishDate 2025-06-01
publisher Copernicus Publications
record_format Article
series Earth System Science Data
spelling doaj-art-4cdab28e02f54420802b5887d607e16c2025-08-20T03:30:28ZengCopernicus PublicationsEarth System Science Data1866-35081866-35162025-06-01172873288510.5194/essd-17-2873-2025Global patterns and drivers of soil dissolved organic carbon concentrationsT. Ren0T. Ren1A. Cai2Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, ChinaDepartment Soil Science and Environmental Analyses, Institute of Soil Science and Plant Cultivation-State Research Institute, Czartoryskich St. 8, 24–100 Puławy, PolandInstitute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing, 100081, China<p>Dissolved organic carbon (DOC) constitutes the most active carbon pool in soils and plays critical roles in soil carbon cycling, plant productivity, and global climate change. Accurately assessing soil DOC quantity is essential to elucidate ecosystem functions and services. However, global driving factors and the spatial distribution of soil DOC remain poorly quantified, largely due to limited large-scale data. Here, we compile a comprehensive global database of soil DOC concentrations, encompassing 12 807 observations extracted from 975 scientific publications published between 1984 and 2020. We also record detailed geographic locations, climatic variables, and soil properties as predictors. Machine learning techniques were employed, including 10-fold cross-validation and evaluating model performance by <span class="inline-formula"><i>R</i><sup>2</sup></span> and root mean square error values, to predict the relative importance of various predictors and the global distribution of soil DOC concentrations. Worldwide soil DOC concentrations ranged from 0.04 to 7859 mg kg<span class="inline-formula"><sup>−1</sup></span>, averaging 222.78 mg kg<span class="inline-formula"><sup>−1</sup></span>. The 14 selected predictors, including elevation, soil properties, and climate, explained 63 % of the variance in soil DOC concentrations. Elevation played the most important predictor for soil DOC prediction, followed by soil organic carbon, seasonal variability of temperature, and soil clay content. Soil DOC decreases initially but increases when soil clay content exceeds 20 % and seasonal variability of temperature exceeds 0.7. Using these findings, a global map of predicted soil DOC concentrations was produced at a 0.05° by 0.05° resolution. Global soil DOC concentrations generally increased from the Equator to the poles wherein the topsoil layer (0–30 cm) holds 13.47 Pg of soil DOC with substantial variations across continents. These results inform soil management practices strategies, ecosystem services evaluations, and climate change mitigation efforts. Furthermore, we envision integrating our database with other carbon pools to advance understanding of total soil carbon turnover and to refine Earth system models. The dataset is publicly available at <a href="https://doi.org/10.6084/m9.figshare.28574183">https://doi.org/10.6084/m9.figshare.28574183</a> (Ren and Cai, 2025).</p>https://essd.copernicus.org/articles/17/2873/2025/essd-17-2873-2025.pdf
spellingShingle T. Ren
T. Ren
A. Cai
Global patterns and drivers of soil dissolved organic carbon concentrations
Earth System Science Data
title Global patterns and drivers of soil dissolved organic carbon concentrations
title_full Global patterns and drivers of soil dissolved organic carbon concentrations
title_fullStr Global patterns and drivers of soil dissolved organic carbon concentrations
title_full_unstemmed Global patterns and drivers of soil dissolved organic carbon concentrations
title_short Global patterns and drivers of soil dissolved organic carbon concentrations
title_sort global patterns and drivers of soil dissolved organic carbon concentrations
url https://essd.copernicus.org/articles/17/2873/2025/essd-17-2873-2025.pdf
work_keys_str_mv AT tren globalpatternsanddriversofsoildissolvedorganiccarbonconcentrations
AT tren globalpatternsanddriversofsoildissolvedorganiccarbonconcentrations
AT acai globalpatternsanddriversofsoildissolvedorganiccarbonconcentrations