Explanatory powers (R2 values) of final models for the effects of climate and soil fertility on biomass conversion factors (BCFs, Mg m−3).

Models ‘Climate’ denoted that the explanatory variables were selected by a backward stepwise procedure from mean annual temperature (MAT, °C), mean annual precipitation (MAP, 100 mm) and interactions between these variables, as well as the quadratic terms of MAT and MAP, which had nonlinear relationships with several BCFs (see Fig. 1 and 2). Similarly, models ‘Climate+Soil’ denoted that the explanatory variables were selected by a backward stepwise procedure from MAT, MAP, soil fertility class, interactions between these variables and quadratic terms of continuous variables (MAT and MAP). Details of final models ‘Climate’ and ‘Climate+Soil’ were given in Table S2 and S3 in File S2, respectively. Significance of a model: ns, not significant (P>0.05);*, P**, P