Figure 2.

[CO₂] and temperature in FACE rings and HNT tents. Environmental parameters showing daily ambient [CO₂] concentration (green line) and e[CO₂] concentration (blue lines) averaged across three independent FACE rings during 2017 (A); daily ambient [CO₂] concentration (green line), and e[CO₂] concentration (blue line) in night temperature tent during 2018; daily night time temperature under ambient (gray line), HNT tent (orange line), and HNT + e[CO₂] (e[CO₂] + HNT) tent (purple line) (B); e[CO₂] exposure during 2017 and 2018 experiments was initiated at seven days after transplanting and continued until physiological maturity. HNT was started at panicle initiation and continued until physiological maturity.