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 degrees C) of these Eucalyptus species ranged from zero for E. forrestiana to 5.4 +/- 2.2 mu g g(-1) h(-1) (or 871 +/- 33 mu g m(-2) h(-1)) for E. globulus. The dominant monoterpene compounds emitted from these Eucalyptus species were alpha-pinene, 1,8-cineole, beta-pinene and limonene. The normalised isoprene emission rates (leaf temperature 30 degrees C, PAR flux 1000 mu mol m(-2) s(-1)) ranged from 5.3 +/- 1.6 (E. botryoides) to 69 +/- 34 mu g 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 (beta value) of the four Eucalyptus species was 0.103 +/- 0.012 K-1. (C) 1999 Elsevier Science Ltd. All rights reserved.