Contribution of some Mediterranean plants to BVOC in the atmosphere of an open and a closed environment: a preliminary study

摘要

Terpenes (monoterpenes and sesquiterpenes) were measured under a closed environment (with a canopy structure) and an open environment (without a canopy structure). Terpenes were sampled both directly from vegetation (Cistus albidus, Rosmarinus officinalis, Pinus halepensis and Quercus coccifera) and in the atmosphere. Results show that the four species are influenced by the environmental structure. This influence is especially important for Q. coccifera and R. officinalis which present higher emission rates at the open and the closed environment, respectively. Of special interest is the fact that sesquiterpene emissions of C. albidus and P. halepensis are higher under the open environment, since it may indicate that these compounds are dependent on light. Terpenes do not follow a lengthwise gradient in the atmosphere. However, some exceptions have been found for α-pinene and sesquiterpene concentrations. Monoterpene concentrations are significantly higher in the open atmosphere. This demonstrates that the canopy does not minimize terpene volatilization and that terpene concentration in the atmosphere is mostly dependent on plant contribution but litter seems to be another important source of terpenes.