Monoterpene and isoprene emissions from 15 Eucalyptus species in Australia

Monoterpene and isoprene emission rates of 15 Eucalyptus species were measured using an air exchange chamber technique and GC-FID analysis. The normalised monoterpene emission rates (leaf temperature 30°C) of these Eucalyptus species ranged from zero for E. forrestiana to 5.4±2.2 μg g−1 h−1 (or 871±33 μg m−2 h−1) for E. globulus. The dominant monoterpene compounds emitted from these Eucalyptus species were α-pinene, 1,8-cineole, β-pinene and limonene. The normalised isoprene emission rates (leaf temperature 30°C, PAR flux 1000 μmol m−2 s−1) ranged from 5.3±1.6 (E. botryoides) to 69±34 μg g−1 h−1 (E. globulus) or from 0.74 (E. cladocalyx) to 9.5 mg m−2 h−1 (E. rudis). Based on monoterpene emission rate data from four Eucalyptus species (E. globulus, E. robusta, E. rudis, and E. sargentii), there were clear exponential relationships between leaf temperature and monoterpene emission rate for these Eucalyptus species. The mean exponential value (β value) of the four Eucalyptus species was 0.103±0.012 K−1.