Genetic structure and diversity of the endangered fir tree of Lebanon (Abies cilicica Carr.): implications for conservation

• Published in: PloS one Vol. 9; no. 2; p. e90086
• Main Authors: Awad, Lara, Fady, Bruno, Khater, Carla, Roig, Anne, Cheddadi, Rachid
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27-02-2014; Public Library of Science (PLoS)
• Subjects: Abies; Abies - genetics; Agriculture; Alleles; Analysis; Bayesian analysis; Biodiversity; Biogeography; Biological evolution; Biology; Bottlenecks; Climate change; Conservation; Conservation of Natural Resources; Demographics; Demography; Dispersal; Dispersion; Egyptian civilization; Endangered Species; Equilibrium conditions; Evolution; Evolutionary genetics; Forests; Genetic diversity; Genetic drift; Genetic structure; Genetic Variation; Genetics, Population; Geography; Life Sciences; Linkage Disequilibrium; Local population; Mediterranean Region; Microsatellite Repeats; Microsatellites; Migration; Plant diversity; Population; Population genetics; Population number; Population structure; Populations; Protection and preservation; Mediterranean Region; Lebanon; endangered; genetic structure; conservation; diversity of the fir tree of Lebanon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0090086

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.