Note: The range of BNPP is estimated based on the BNPP and the turn-over rate of belowground biomass determined in several studies on the Mongolian steppes (Chai et al., 2014; Hou et al., 2014) and the measurement of above- and belowground biomass (0-70 cm) in this experiment. Different lowercase letters indicate significant differences among steppe types at P < 0.05 (Duncan’s test).