Fig. 2: Long-term trends are different between monoterpene enantiomers, especially during daylight hours.
From: Chiral monoterpenes reveal forest emission mechanisms and drought responses
Monoterpene and isoprene data are divided into five stages, indicated by the bands: pre-drought (PD), early drought (ED), severe drought (SD), deep-water rewet (DRW) and rain rewet (RRW). The timing of the 13CO2 pulses is indicated by the dotted black lines. a, Daytime isoprene and total monoterpene volume mixing ratios (VMR). The shaded region around the lines represents the absolute measurement uncertainty. b, Average daytime VMR for (−)-α-pinene and (+)-α-pinene and other monoterpenes. c, Average night-time VMR for (−)-α-pinene and (+)-α-pinene and other monoterpenes. For b and c, the shaded region around the lines represents the calculated measurement uncertainty. d, Soil moisture (SM) and relative humidity (RH). Note the different scales for enantiomers. e, Pie charts showing the daytime composition of the enantiomeric monoterpenes during each stage. Other monoterpenes includes (−)-camphene, (+)-camphene, (−)-limonene, (+)-limonene and γ-terpinene.
