Figure 2. Heterotrophic respiration (R_h) response to the various temperature treatments under four environmental change scenarios, including the control, changes in precipitation amount (P_cha), gradual increases in concentrations of atmospheric CO₂ (C_inc) and their combinations (P_cha × C_inc).

Data are means ± standard error, differences letters bars indicate significant (p < 0.05) differences between means. (BCF: Boreal coniferous forest; TMF: Temperate mixed forest; DBF: Warm-temperate deciduous broadleaf forest; MStp: Meadow steppe; TStp: Typical steppe; DStp: Desert steppe)