Additional information
Supplementary Information accompanies this paper at
https://doi.org/…
Fig. S1 Correlation between NP-induced changes in soil total N content
and NP-induced changes in plant N content. ΔPTN equals plant total
nitrogen under concurrent N+P treatment minus plant total nitrogen under
N only condition. Additions; ΔSTN equals soil total nitrogen under
concurrent N+P treatment minus soil total nitrogen under N only
condition. The log-transformation was used to producing variables
following normal distribution.
Fig. S2 Bivariate correlations between variables used in structure
equation models (observational dataset)
Fig. S3 Structural equation models of meteorology, plant, edaphic and
microbial biomass as predictors of CH4 uptake for (a)
control (n=96, χ2=2.041, DF=2, CFI=1, NFI=0.99), (b) N
addition only (n=96, χ2=0.667, DF=2, CFI=1,
NFI=0.997), (c) P addition only (n=96, χ2=1.946, DF=2,
CFI=1, NFI=0.991) and (d) concurrent N+P additions (n=96,
χ2=2.079, DF=2, CFI=1, NFI=0.99) (black lines
represent positive paths; red lines represent negative paths; solid
lines indicate significant impacts [p<0.05]; dotted lines
indicate non-significant impacts [p>0.05]).
Fig. S4. Spatial distribution of the data points for the whole dataset
used for meta-analysis; 382 data points distributed across the global
grasslands, covering major grassland types, spanning major climate zones
Fig. S5. The correlation matrix of the key variables in the dataset used
for meta-analysis (noted most variables are not in normal distribution,
indicating the needs of log-transformation in further analysis and model
development)
Fig. S6. Correlation between NH4+ and
total inorganic N
(NH4++NO3-).
Fig. S7. Comparison of modeled CH4 with the compiled
CH4 uptake.
Fig. S8. Frequency distribution of the best estimates of
CH4 oxidation across global grasslands (CK:
pre-industrial N and P; N: the model simulation with pre-industrial P
and contemporary N inputs; P: N: the model simulation with contemporary
P and pre-industrial N inputs; NP: model simulations with contemporary N
and P depositions).
Table S1 Correlation coefficients for the regression between independent
variables and CH4 uptake rates based on the
comprehensive data (R2 = 0.44; P < 0.001);
it is used as the empirical model for global estimation of N and P
impacts on CH4 uptake in grasslands
Competing interests: The authors declare no competing
interests.