Monoterpene and isoprene emissions from 15 Eucalyptus species in Australia

Monoterpene and isoprene emission rates of 15 Eucalyptus species were measu red using an air exchange chamber technique and GC-FID analysis. The normal ised monoterpene emission rates (leaf temperature 30 degrees C) of these Eu calyptus 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 mo noterpene compounds emitted from these Eucalyptus species were alpha-pinene , 1,8-cineole, beta-pinene and limonene. The normalised isoprene emission r ates (leaf temperature 30 degrees C, PAR flux 1000 mu mol m(-2) s(-1)) rang ed from 5.3 +/- 1.6 (E. botryoides) to 69 +/- 34 mu g g(-1) h(-1) (E. globu lus) or from 0.74 (E, cladocalyx) to 9.5 mg m(-2) h(-1) (E. rudis). Based o n monoterpene emission rate data from four Eucalyptus species (E. globulus, E. robusta, E. rudis, and E. sargentii), there were clear exponential rela tionships between leaf temperature and monoterpene emission rate for these Eucalyptus species. The mean exponential value (beta value) of the four Euc alyptus species was 0.103 +/- 0.012 K-1. (C) 1999 Elsevier Science Ltd. All rights reserved.