Table 1.

R² values of multiple regression analyses of soil carbon, nitrogen, and phosphorus concentrations for the observational studies. Abbreviations: T, mean annual temperature; P, mean annual precipitation; A, aridity; S, FAO soil classification; E, type of ecosystem. Letter combinations indicate which explanatory terms are included in a model. Values in bold indicate significant effects (p<0.05).

DOI: http://dx.doi.org/10.7554/eLife.23255.010

	[C]	[N]	[P]
T	0.051	0.012	0.018
P	0.222	0.061	0.007
A	0.319	0.181	0.001
S	0.334	0.179	0.107
E	0.420	0.215	0.158
TP	0.342	0.190	0.035
TA	0.331	0.201	0.070
TS	0.494	0.252	0.248
TE	0.509	0.288	0.285
PA	0.386	0.213	0.018
PS	0.562	0.230	0.166
PE	0.510	0.270	0.156
AS	0.492	0.349	0.212
AE	0.514	0.340	0.261
SE	0.700	0.350	0.359
TPA	0.424	0.285	0.115
TPS	0.685	0.349	0.322
TPE	0.583	0.358	0.322
TAS	0.569	0.450	0.361
TAE	0.566	0.446	0.374
TSE	0.758	0.411	0.484
PAS	0.564	0.418	0.256
PAE	0.577	0.432	0.307
PSE	0.743	0.409	0.418
ASE	0.671	0.554	0.479
TPAS	0.621	0.511	0.469
TPAE	0.617	0.542	0.434
TPSE	0.799	0.493	0.562
TASE	0.730	0.668	0.582
PASE	0.726	0.632	0.542
TPASE	0.771	0.727	0.629