title: Population differentiation in a Mediterranean relict shrub: the potential role of local adaptation for coping with climate change.
abstract: Plants can respond to climate change by either migrating, adapting to the new conditions or going extinct. Relict plant species of limited distribution can be especially vulnerable as they are usually composed of small and isolated populations, which may reduce their ability to cope with rapidly changing environmental conditions. The aim of this study was to assess the vulnerability of Cneorum tricoccon L. (Cneoraceae), a Mediterranean relict shrub of limited distribution, to a future drier climate. We evaluated population differentiation in functional traits related to drought tolerance across seven representative populations of the species' range. We measured morphological and physiological traits in both the field and the greenhouse under three water availability levels. Large phenotypic differences among populations were found under field conditions. All populations responded plastically to simulated drought, but they differed in mean trait values as well as in the slope of the phenotypic response. Particularly, dry-edge populations exhibited multiple functional traits that favored drought tolerance, such as more sclerophyllous leaves, strong stomatal control but high photosynthetic rates, which increases water use efficiency (iWUE), and an enhanced ability to accumulate sugars as osmolytes. Although drought decreased RGR in all populations, this reduction was smaller for populations from the dry edge. Our results suggest that dry-edge populations of this relict species are well adapted to drought, which could potentially mitigate the species' extinction risk under drier scenarios. Dry-edge populations not only have a great conservation value but can also change expectations from current species' distribution models.
authors.affiliation: LINCGlobal, Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 dpdo., 28006, Madrid, Spain. ana.lazaronogal@gmail.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Lázaro-Nogal
authors.affiliation: Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Tulipán s/n, 28933, Móstoles, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Matesanz
authors.affiliation: Department of Plant Physiology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014, Tartu, Estonia.|Tartu Observatory, Tõravere, 61602, Tartumaa, Estonia.
authors.forename: Lea
authors.initials: L
authors.lastname: Hallik
authors.affiliation: Department of Plant Physiology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014, Tartu, Estonia.
authors.forename: Alisa
authors.initials: A
authors.lastname: Krasnova
authors.affiliation: LINCGlobal, Institut Mediterrani d'Estudis Avançats, IMEDEA-CSIC, Miquel Marquès 21, 07190, Esporles, Mallorca, Spain.
authors.forename: Anna
authors.initials: A
authors.lastname: Traveset
authors.affiliation: LINCGlobal, Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, MNCN-CSIC, Serrano 115 dpdo., 28006, Madrid, Spain.|Departamento de Biología y Geología, ESCET, Universidad Rey Juan Carlos, Tulipán s/n, 28933, Móstoles, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Valladares
mesh_terms: D000064:Acclimatization; D000222:Adaptation, Physiological; D050260:Carbohydrate Metabolism; D002980:Climate; D057231:Climate Change; D055864:Droughts; D017753:Ecosystem; D019684:Magnoliopsida / Q000378:metabolism / Q000502:physiology*; D019083:Mediterranean Region; D010641:Phenotype; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology; D013312:Stress, Physiological; D014867:Water / Q000502:physiology*
chemical_list: D014867:Water
keywords: Distribution range; Drought; Dry edge; Functional traits; Phenotypic plasticity