title: Genetic structure and diversity of the endangered fir tree of Lebanon (Abies cilicica Carr.): implications for conservation.
abstract: The threatened conifer Abies cilicica currently persists in Lebanon in geographically isolated forest patches. The impact of demographic and evolutionary processes on population genetic diversity and structure were assessed using 10 nuclear microsatellite loci. All remnant 15 local populations revealed a low genetic variation but a high recent effective population size. FST -based measures of population genetic differentiation revealed a low spatial genetic structure, but Bayesian analysis of population structure identified a significant Northeast-Southwest population structure. Populations showed significant but weak isolation-by-distance, indicating non-equilibrium conditions between dispersal and genetic drift. Bayesian assignment tests detected an asymmetric Northeast-Southwest migration involving some long-distance dispersal events. We suggest that the persistence and Northeast-Southwest geographic structure of Abies cilicica in Lebanon is the result of at least two demographic processes during its recent evolutionary history: (1) recent migration to currently marginal populations and (2) local persistence through altitudinal shifts along a mountainous topography. These results might help us better understand the mechanisms involved in the species response to expected climate change.
authors.affiliation: University of Montpellier II, Institute of Evolutionary Sciences, CNRS UMR 5554, Montpellier, France.
authors.forename: Lara
authors.initials: L
authors.lastname: Awad
authors.affiliation: INRA, UR629, Ecologie des Forêts Méditerranéennes (URFM), Domaine St Paul, Avignon, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Fady
authors.affiliation: Center for Remote Sensing, National Council for Scientific Research-Lebanon, Bir Hassan, Beirut, Lebanon.
authors.forename: Carla
authors.initials: C
authors.lastname: Khater
authors.affiliation: INRA, UR629, Ecologie des Forêts Méditerranéennes (URFM), Domaine St Paul, Avignon, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Roig
authors.affiliation: University of Montpellier II, Institute of Evolutionary Sciences, CNRS UMR 5554, Montpellier, France.
authors.forename: Rachid
authors.initials: R
authors.lastname: Cheddadi
mesh_terms: D028202:Abies / Q000235:genetics*; D000483:Alleles; D044822:Biodiversity; D003247:Conservation of Natural Resources; D056727:Endangered Species; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D015810:Linkage Disequilibrium; D019083:Mediterranean Region; D018895:Microsatellite Repeats