A synthesis of ecosystem aboveground productivity and its process variables under simulated drought stress

1. Projected increases in drought duration and intensity under climate change considerably affect aboveground productivity (ANPP) and associated process variables (photosynthesis rates (Pn), stomatal conductance (gs), soil respiration (Rs), and soil water content (SWC)). 2. Although ANPP has been extensively studied across the ecosystems, there is little consensus on how the spatiotemporal patterns of ANPP will be altered with increasing drought stress. Here, we present a global meta-analysis of ANPP and the four variables (610 observations from 78 studies) for drought duration, intensity, and their combination. 3. Forest-ANPP had stronger negative responses to long-term drought (34.44%; ≥ 4 yrs) than short-term drought (10.78%; ≤ 1 yr), and decreased more in Mediterranean forests than in tropical forests. Decreases in Pn and gs were strongest under long-term moderate drought. In the short term, Rs increased by 5.66% under light drought, but decreased by 14.12% and 28.43% under moderat...