title: Functional ecology of ecotypic differentiation in the Californian serpentine sunflower (Helianthus exilis).
abstract: * Here, we examined phenotypic differences between locally adapted serpentine and riparian populations of the serpentine sunflower Helianthus exilis from northern California, USA. * Within a common environment, plants from serpentine and riparian sites were grown in regular potting soil or serpentine soil. Physiology, morphology, phenology and fitness-related traits were measured. * Overall, riparian plants grew more rapidly, attained a larger final size, produced larger leaves, and smaller flowering heads. Riparian plants also invested less in root biomass and were more water-use-efficient than the serpentine plants. Serpentine and riparian plants also differed in leaf concentrations of boron, magnesium, sodium and molybdenum. * These ecotypic differences suggest contrasting adaptive strategies to cope with either edaphic stress in serpentine sites or intense above-ground competition at riparian sites. There was a significant population origin x soil type crossing interaction in one fitness trait (average dry weight) that mirrored local adaptation previously documented for these riparian and serpentine ecotypes. However, because all other fitness traits did not exhibit this crossing interaction in our common garden study, it is possible that phenotypic differences underlying local adaptation may be amplified in the field as a result of biotic and abiotic interactions.
authors.affiliation: Department of Botany, 6270 University Boulevard, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
authors.forename: Julianno B M
authors.initials: JBM
authors.lastname: Sambatti
authors.affiliation: Department of Plant Sciences, University of California, Davis. One Shields Avenue, 95616 Davis CA, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Rice
mesh_terms: D002140:California; D002247:Carbon Isotopes / Q000378:metabolism; D002980:Climate; D004463:Ecology; D017753:Ecosystem; D035264:Flowers / Q000502:physiology; D018525:Germination; D006368:Helianthus / Q000737:chemistry / Q000254:growth & development / Q000502:physiology*; D007287:Inorganic Chemicals / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis; D012987:Soil
chemical_list: D002247:Carbon Isotopes; D007287:Inorganic Chemicals; D009930:Organic Chemicals; D012987:Soil