Auxiliary material for
Estimating the soil carbon sequestration potential of China’s Grain for Green Project
Authors: Shengwei Shi 1, 2, 3*and Pengfei Han 1, 2
Affiliations: 1. State Key Laboratory of Atmospheric Boundary Layer Physics and
Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of
Sciences, Beijing, 100083, PR China；2. University of Chinese Academy of Sciences,
Beijing 100049, PR China；3. College of Forestry, Northwest A & F University,
Yangling, Shaanxi, 712100, PR China
Introduction
The data used to fit SOC dynamics after restoration was established combining the
results from the literature survey (211 articles ) and field experiments in Qinghai
province (a total of 58 sites). We provide the essential materials, including 3
documents (appendix A.docx, appendix B.docx, and appendix C.docx) and 4 tables
(Ts 01.txt, Ts 02.txt, Ts 03.txt and Ts 04.txt), to enable readers to better understand the
paper. The documents and tables included:
1. Appendix A.docx The data set established using literature references and the
principles of data quality control. We introduce the data sources and data quality
control.
2. Appendix B.docx Basic information on soil sampling approach and plot sizes for
the field observation on the Qinghai Plateau.
3. Appendix C.docx The derivation of the coefficient (γ) for the adjustment of SOC
density at h depths to the top 20 cm for a given soil type in this study. We show the
method used to calculate a coefficient for the adjustment of SOC density at h depths
to the top 20 cm of corresponding soil types. In order to establish a general model to
fit relative SOC change at the same sample depths and include more experiment
results, the SOC storage changes with irregular sample depths (h) were adjusted to
those of the top 20 cm of the sample using the this coefficient.
4. Ts 01.txt List of supporting studies obtained from literature references for SOC
dynamics after forestation on cropland, forestation on barren land, and conversion
from cropland to grassland.
4.1 Column “No.”, the number of data in our data set in this study.
4.2 Column “Province”, the province name of location for each sample site in China.
4.3 Column “Country”, the country name of location for each sample site in China.
4.4 Column “Zone”, the forestry zone.
4.5 Column “R-mode”, the type of restoration.
4.6 Column “land”, the types of land-use prior to restoration.
4.7 Column “Age”, the plantation age.
4.8 Column “SOC-F”, the SOC content in forested plots in the top 20 cm depths.
4.9 Column “SOC-Ref”, the SOC content in reference plots in the top 20 cm depths.
4.10 Column “SOC-Ref”, the number of repetition in forested plots at one sampling
site.
4.11 Column “N-f”, the number of repetition in forested plot at one sampling site.
4.12 Column “N-Ref”, the number of repetition in reference plot at one sampling site.
4.13 Column “Restoration type”, the restoration properties, A is planted by human, N
is total relaying on naturally succession.
4.14 Column “SA”, study design for abbreviation: 1 for chronosequence, 2 for paired
–plot, and 3 for retrospective.
4.15 Column “Authors”, the study authors.
5. Ts 02.txt Basic information of soil sampling sites on the Qinghai Plateau.
5.1 Column “Site”, the name location of sample site on the Qinghai Plateau.
5.2 Column “Restoration type”, the types of restoration according to prior land-use.
5.3 Column “Ele.”, the elevation of sample site.
5.4 Column “MAP”, the mean annual precipitation (mm) of sample site.
5.5 Column “MAT”, the mean annual temperature (℃) of sample site.
5.6 Column “Dominated species”, the main planted species in the forested plots at
each sample site.
5.7 Column “O layer”, the depths of forest floor in the forested plots at each sample
site.
5.8 Column “Age”, the afforestation age (year).
5.9 Column “Post-SOC content”, the SOC content in forest plots in the top 20 cm
depths.
5.10 Column “Before-SOC content”, the SOC content in reference plots in the top 20
cm depths.
5.11 Column “Georeference position”, the geographical position of sample site.
6. Ts 03.txt Results of type III tests for all fixed effects on the response of SOC stocks
to forestation in China
6.1 Column “Effect”, the fixed effects included in the linear mixed model.
6.2 Column “Numerator df”, the freedom of the fixed effect.
6.3 Column “F value”, the F value in the type III tests.
6.4 Column “Pr>F§”, represents the probability of an effect in the presence of all the
other effects in the model.
7. Ts 04.txt The annual conversion area (ha) under different types restoration of the
GGP in China during 1999~2012.
7.1 Column “Restoration/zone”, the types of restoration and forestry zone in this
study.
7.2 Column “1999” to “2012”, the annual conversion area (ha) at different forestation
zones under of China’s Grain for Green Project during 1999~2012.