title: Differential response of delta13C and water use efficiency to arbuscular mycorrhizal infection in two aridland woody plant species.
abstract: During a revegetation field experiment in Southeast Spain, we measured foliar carbon isotope ratios (delta13C) and gas exchange parameters in order to evaluate the influence of arbuscular mycorrhizal (AM) infection on the water use efficiency (WUE) of two semiarid woodland species. WUE during drought was significantly enhanced by inoculation with Glomus intraradices in Olea europaea ssp sylvestris, but not in Rhamnus lycioides. While Olea is a long-lived, slow-growing evergreen tree with a conservative water use strategy, Rhamnus is a drought-deciduous shrub with a shorter lifespan; these differences may explain their dissimilar patterns of physiological response to inoculation with the same AM fungus. Differences in delta13C and WUE between Olea and Rhamnus were larger when comparing AM inoculated than non-inoculated seedlings. This result suggests that some of the interspecific variability in delta13C observed for aridland plant communities may be due to different physiological responses to mycorrhization.
authors.affiliation: Center for Conservation Biology, The University of California, Riverside, CA 92521-0124, USA. nachoq@ucrac1.ucr.edu
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: Querejeta
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Barea
authors.forename: Michael F
authors.initials: MF
authors.lastname: Allen
authors.forename: Fuensanta
authors.initials: F
authors.lastname: Caravaca
authors.forename: Antonio
authors.initials: A
authors.lastname: Roldán
mesh_terms: D000704:Analysis of Variance; D002247:Carbon Isotopes / Q000378:metabolism*; D003124:Colorimetry; D013058:Mass Spectrometry; D038821:Mycorrhizae; D031658:Olea / Q000378:metabolism* / Q000382:microbiology; D031955:Rhamnus / Q000378:metabolism* / Q000382:microbiology; D013030:Spain; D014867:Water / Q000378:metabolism*
chemical_list: D002247:Carbon Isotopes; D014867:Water