Table 1 Spatially explicit environmental data used for SOC stock modeling
Groups | Variables | Resolution | Source |
|---|---|---|---|
Paleoclimate | Annual mean temperature, mean diurnal range, temperature seasonality, maximum temperature of the warmest month, minimum temperature of the coldest month, annual temperature range, mean temperature of the wettest quarter, mean temperature of the driest quarter, mean temperature of the warmest quarter, the mean temperature of the coldest quarter, annual precipitation, precipitation of the wettest month, precipitation of the driest month; precipitation seasonality, precipitation of the wettest quarter, precipitation of the driest quarter, precipitation of the warmest quarter, precipitation of the coldest quarter | 2.5 arc minutes (mid-Holocene, Last Glacial Maximum) | WorldClim [47] |
Modern climate | Mean monthly temperature, mean monthly precipitation | 0.025°, monthly (1981–2011) | Zhao et al. [48] |
10 m wind speed, surface pressure, 2 m dewpoint temperature, runoff, surface runoff, sub-surface runoff, total evaporation, evaporation from bare soil, evaporation from vegetation transpiration, potential evaporation, snow cover, snowfall, temperature of snow layer | 0.1°, monthly (2001–2018) | ERA5 from ECMWF [49] | |
Wet deposition of inorganic nitrogen | 1Â km, yearly (2005, 2010, 2015) | Jia et al. [50] | |
Terrestrial evapotranspiration | 0.1 , monthly (2000–2017) | Ma et al. [51] | |
Snow depth | 25 km, daily (2000–2018) | Dai et al. [52] | |
Photosynthetically active radiation (PAR) | 0.05°, monthly (2000–2014) | GLASS [53] | |
Vegetation | Fraction of absorbed photosynthetically active radiation (FAPAR) | 1 km, monthly (2000–2014) | C3S [54] |
Gross primary productivity (GPP) | 1 km, 8-day (2001–2016) | MODIS (MOD17A2H) from LP DAAC [55] | |
Net primary productivity (NPP) | 1 km, yearly (2001–2014) | MODIS (MOD17A3) from LP DAAC [55] | |
Leaf area index (LAI) | 1 km, 8-day (2000–2016) | Yuan et al. [56] | |
Normalized differential vegetation index (NDVI) | 1 km, monthly (2001–2017) | MODIS (MOD13A3) from LP DAAC [55] | |
Sun-Induced Chlorophyll Fluorescence (SIF) | 0.5°, biweekly (2007–2016) | Joiner et al. [57] | |
Enhanced vegetation index (EVI) | 1 km, monthly (2001–2017) | MODIS (MOD13A3) from LP DAAC [55] | |
Vegetation type | 1Â km, 2010 | Ran et al. [36] | |
Root depth | 1°, 1986–1995 | Schenk et al. [58] | |
Total pant-available soil water storage capacity of the rooting zone | 1°, 1986–1995 | Kleidon et al. [59] | |
Aboveground biomass carbon, belowground biomass carbon | 300Â m, 2010 | Spawn et al. [60] | |
Topography | Elevation, slope, curvature, plane curvature, curve curvature, aspect, hillshade | 1Â km | Tang et al. [27] |
Soil | PH value (H2O), total N, total P, total K, alkali-hydrolysable N, available P, available K, cation exchange capacity (CEC), exchangeable H+, exchangeable Al3+, exchangeable Ca2+, exchangeable Mg2+, exchangeable K+, exchangeable Na+, porosity, particle-size distribution (sand, silt, clay), root abundance | 30 arc-seconds (about 1Â km) | Shangguan et al. [33] |
Soil type | 1Â km | RESDC [61] | |
Soil erosion intensity | 300Â m, 2005, 2015 | Zhang et al. [45] | |
Soil temperature; Soil moisture | 0.25°, monthly (2000–2015) | GLDAS-Noah [62] | |
Frozen soil distribution | 1Â km, 2000 | Ran et al. [28] | |
Permafrost zonation index | 1Â km, 2019 | Cao et al. [44] | |
Soil microbial biomass carbon, soil microbial biomass nitrogen, C:N ratio of soil microbial biomass | 0.05°, 1970s–2012 | Xu et.al. [63] | |
Human footprint | Population density | 1 km, yearly (2000–2012) | WorldPop [64] |
Human footprint | 1Â km, 2009 | Venter et al. [24] |