title: Leaf allocation patterns and 13C and 15N natural abundances of tropical lianas (Passiflora sp.) as dependent on external climbing support.
abstract: The transformation from self-supporting lianas to host-supported climbing lianas is related to re-allocation of biomass and nutrients among plant organs. Therefore, first, variations in leaf mass per area (LMA), leaf carbon and nitrogen allocation and (13)C and (15)N natural abundances were analysed among three tropical Passiflora species (P. edulis, P. ligularis, and P. tripartita) in a greenhouse study. Second, the influence of a climbing support was considered for each species and parameter. P. ligularis leaves were most enriched in (13)C in both treatments when compared with the other two species. This enrichment was caused by a high LMA, which is related to a high internal resistance to CO(2) diffusion. For P. edulis and P. tripartita, δ(13)C was additionally increasing with nitrogen content per area. Generally, there were no differences when considering carbon and nitrogen allocation to leaves of host-supported and self-supporting lianas. The only hints towards increased investment into leaves after the transition from self-supporting to host-supported stages could be seen by a trend to increased leaf areas and masses. δ(13)C values of supported P. edulis or P. tripartita plants were significantly increasing faster than those of non-supported plants once the interactions of leaf mass or nitrogen content per area were accounted for. Hence, the offer of a climbing support had only a minor impact on δ(13)C or δ(15)N values in vitro, but this could be different with increasing age of lianas in vivo.
authors.affiliation: Institute of Systematic Botany and Ecology, University of Ulm, Ulm, Germany. martin.werth@uni-ulm.de
authors.forename: Martin
authors.initials: M
authors.lastname: Werth
authors.forename: Ann-Kathrin
authors.initials: AK
authors.lastname: Spiegel
authors.forename: Marian
authors.initials: M
authors.lastname: Kazda
mesh_terms: D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis*; D004777:Environment; D009587:Nitrogen Isotopes / Q000032:analysis*; D029598:Passiflora / Q000737:chemistry* / Q000502:physiology; D010788:Photosynthesis; D018515:Plant Leaves / Q000737:chemistry* / Q000502:physiology; D014867:Water / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D014867:Water; D002245:Carbon Dioxide