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

PLoS One. 2014 Feb 27;9(2):e90086. doi: 10.1371/journal.pone.0090086. eCollection 2014.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abies / genetics*
  • Alleles
  • Biodiversity*
  • Conservation of Natural Resources
  • Endangered Species*
  • Genetic Variation
  • Genetics, Population
  • Geography
  • Linkage Disequilibrium
  • Mediterranean Region
  • Microsatellite Repeats

Grants and funding

This paper represents a part of the doctoral research of Lara Awad who acknowledges a scholarship from the Institut Ecologie et Environnement (INEE) of the Centre National de la Recherche Scientifique (CNRS) (Contract number 245303) (http://www.cnrs.fr/inee/) and (http://www.cnrs.fr/index.php). Fieldwork in Lebanon was facilitated by a financial support from the Grant Research Program (GRP) of the National Council for Scientific Research-Lebanon (NCSR) (http://www.cnrs.edu.lb/). The stay of Lara Awad at INRA-URFM for the laboratory work was facilitated by a financial support from the EcoChange project (http://www.ecochange-project.eu/ecochange-project). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.