Table S1 Geographic location, climate conditions, and plant diversity in the seventeen forests in western China. MAT: mean annual temperature o o -1 ( C); MAP: mean annual precipitation (mm); △T: Annual temperature range( C); Htree: tree species diversity; T.C: Total organic carbon (mg g ) ; ECa: exchangeable calcium (cmol kg-1). Forest types Plant species Location Elevation MAT MAP △T Htree pH T. C C/N ECa AT2 Boreal forest Schrenk Spruce 48°45' N，87°02' E 1761.00 -2.80 298.00 37.40 0.95 5.13 36.75 17.65 5.39 AT1 Boreal forest Schrenk Spruce 48°21' N，87°08' E 1400.00 -1.00 264.00 37.40 0.86 5.57 19.29 14.83 9.34 TS1 Boreal forest Picea obovata Ledeb 43°29' N，85°58' E 1106.00 4.30 368.00 36.30 0.00 6.66 111.71 13.29 61.32 QL1 Temperate forest Pinus armandii franch 33°26' N，108°23' 1585.00 10.00 944.00 23.30 1.75 5.92 17.33 13.73 10.21 E QL2 Temperate forest Pinus armandii franch 33°26' N，108°23' 1680.00 9.40 987.00 23.30 1.22 6.01 27.24 13.35 11.14 E QL3 Temperate forest Pinus tabulaeformis 33°26' N，108°23' 1816.00 8.60 987.00 23.30 1.71 4.98 18.18 16.85 1.99 E QL4 Temperate forest Pinus tabulaeformis 33°26' N，108°23' 2006.00 8.00 944.00 23.30 0.91 5.69 19.16 12.91 8.24 E GG2 Temperate forest Picea brachytyla 29°35' N，102°01' 2595.00 5.50 1021.00 13.70 1.49 5.39 37.62 12.85 7.50 E GG3 Temperate forest Picea brachytyla 29°35' N，102°03' 2204.00 8.50 1058.00 13.70 2.40 5.67 42.09 12.18 7.48 E GG1 Temperate forest Picea brachytyla 29°34' N，102°00' 3115.00 3.10 1021.00 13.70 0.42 5.55 8.46 12.14 1.10 E ZD1 Subtropical forest Quercus semicarpifolia 27°48' N，99°42' E 3347.00 5.40 810.00 11.80 0.73 5.46 23.79 12.34 7.96 ZD2 Subtropical forest Larix potaninii 27°48' N，99°42' E 3507.00 4.80 810.00 11.80 0.93 4.76 30.81 13.56 2.54 AL1 Subtropical forest Lithocarpusxylocarpum 24°32' N，101°01' 2442.00 13.50 1113.00 10.20 2.25 5.01 91.25 13.91 1.04 E AL2 Subtropical forest Ilex delavayi 24°32' N，101°01' 2654.00 12.30 1113.00 10.20 1.46 4.00 99.30 15.74 0.46 E BN2 Tropical forest Cleistanthus sumatranus 22°25' N，101°27' 1147.00 18.60 1625.00 9.30 3.00 4.71 17.81 11.53 0.68 E BN3 Tropical forest Pometia pinnata Forst 21°57' N，101°12' 649.00 22.70 1398.00 9.30 4.08 4.50 12.73 8.31 1.31 E BN1 Tropical forest Cleistanthus sumatranus 21°27' N，101°17' 730.00 20.70 1499.00 9.30 1.64 7.02 38.08 8.67 1.64 E