title: Effect of intraspecific competition and substrate type on terpene emissions from some Mediterranean plant species.
abstract: Competition is an important factor that has been extensively reported in the Mediterranean area. There is evidence that leaf terpene accumulation may vary between plants growing on calcareous and siliceous soils. In the present study, leaf terpene emissions from potted seedlings of Pinus halepensis, Cistus albidus, and Quercus coccifera, growing under natural environmental conditions on calcareous and siliceous substrates, were studied by using a bag enclosure method. In both substrates, seedlings were potted alone and in intraspecific competition, to examine the effect of substrate type and that of intraspecific competition on terpene emissions. The results showed that competition favored: (i) overall monoterpene and sesquiterpene emissions from Q. coccifera; (ii) overall monoterpene emissions from P. halepensis; (iii) overall sesquiterpene emissions from C. albidus. Substrate type affected terpene emissions to a limited extent and in a species-specific way. Whereas for Q. coccifera, the overall monoterpene emissions and that of Allo-aromadendrene were favored on siliceous substrate, no significant changes were found in emissions from P. halepensis. Only the release of AR-curcumene from C. albidus was higher on siliceous substrate. We also found high variability in terpene emission composition from the study species, particularly for P. halepensis and Q. coccifera. These two species released both monoterpenes and sesquiterpenes, instead of monoterpenes only, as shown in previous studies.
authors.affiliation: Institut Méditerranéen d'Ecologie et Paléoécologie (IMEP) - UMR CNRS 6116, Equipe Ecologie Fonctionnelle, Université de Provence Centre de St Jérôme, Case 421 Avenue Escadrille Normandie Niémen. 13397, Marseille, France. elena.ormeno@univ-cezanne.fr
authors.forename: Elena
authors.initials: E
authors.lastname: Ormeño
authors.forename: Anne
authors.initials: A
authors.lastname: Bousquet-Mélou
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Mévy
authors.forename: Stéphane
authors.initials: S
authors.lastname: Greff
authors.forename: Christine
authors.initials: C
authors.lastname: Robles
authors.forename: Gilles
authors.initials: G
authors.lastname: Bonin
authors.forename: Catherine
authors.initials: C
authors.lastname: Fernandez
mesh_terms: D000704:Analysis of Variance; D029758:Cistus / Q000502:physiology*; D039821:Monoterpenes / Q000737:chemistry / Q000378:metabolism; D028223:Pinus / Q000502:physiology*; D018515:Plant Leaves / Q000502:physiology; D029963:Quercus / Q000502:physiology*; D036226:Seedlings / Q000254:growth & development / Q000378:metabolism; D012987:Soil; D013045:Species Specificity; D013379:Substrate Specificity; D013729:Terpenes / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D039821:Monoterpenes; D012987:Soil; D013729:Terpenes