Total data for global pattern of organic carbon pools in forest soil

Understanding the mechanisms of soil organic carbon (SOC) sequestration in forests is vital to ecosystem carbon budgeting, and helps gain insight in the functioning and sustainable management of world forests. An explicit knowledge of the mechanisms driving global SOC sequestration in forests is still lacking because of the complex interplays between climate, soil and forest type in influencing SOC pool size and stability. Based on a synthesis of 1179 observations from 292 studies across global forests, we quantified the relative importance of climate, soil property and forest type on total SOC content and the specific contents of physical (particulate vs. mineral-associated SOC) and chemical (labile vs. recalcitrant SOC) pools in upper 10 cm mineral soils, as well as SOC stock in the O horizons. The variability in the total SOC content of the mineral soils was better explained by climate (47~60%) and soil factors (26%~50%) than by NPP (10~20%). The total SOC content and contents of par..., We used the Google Scholar (https://scholar.google.com) and China National Knowledge Infrastructure (CNKI, https://www.cnki.net) to search for published papers on studies of SOC in forest ecosystems globally. The searched keywords were “(soil organic matter OR soil carbon OR soil organic carbon physical fractions OR chemical fractions OR particulate OR mineral‐associated OR labile OR recalcitrant) AND (forest OR forest ecosystems)”. Specifically, the searched keywords were in Chinese terminology when using CNKI. The search yielded more than 1000 studies matching those keywords. To avoid bias in selection of publications and to increase the comparability of data, studies that satisfied the following criteria were incorporated into the final dataset for synthesis: (1) field studies conducted with natural and mature forests; (2) studies exclusively concerned with separation of SOC into physical (determined by density or particle size into POC and MAOC, respectively) or chemical (determined..., , # Total\_data

[https://doi.org/10.5061/dryad.ht76hdrp8](https://doi.org/10.5061/dryad.ht76hdrp8)

## Description of the data and file structure

Abbreviations and the units of the variables in the dataset (Total_data.xlsx)

Filling these empty cells in the data file will interfere with a script used to analyze the data, it is necessary to leave these cells empty.

MAT: mean annual temperature(C);

MAP: mean annual precipitation(mm);

PET: potential evapotranspiration;

AI: Aridity Index,MAP/PET;

Soil_order: USDA;

NPP, gC/m²/year;

Elevation: Altitude,(m);

Forest type: Conifer, Broadleaf, mixed Tree; age, years

Soil type: Soil order according to USDA;

BD, bulk density,(g.cm-3);

Sand,Silt,Clay,

SC(Silt+Clay) (%);

Fe,Al. Total Fe/Al,(g·kg-1soil);

Fed. Ald: free Fe and Al oxides.(g kg-1soil); dithionite extractable Fe;

Feo, Alo: amorphous Fe and Al oxides (g·kg-1soil); oxalate extractable Fe and Al;

Fed-Feo: crystalline iron (Fed-Feo);

Fep,Alp:organically-complexed Fe and Al (g...