Magda Bou Dagher-Kharrat

High genetic diversity with moderate differentiation in Juniperus excelsa from Lebanon and the eastern Mediterranean region

Juniperus excelsa constitutes a precious woody species of high ecological value able to grow up to Mountain treeline around the Mediterranean. Nuclear microsatellites were used to shed light on genetic diversity and differentiation of different Mediterranean populations. This information is essential in planning conservation strategies and reforestation programs.

Morphological versus molecular markers to describe variability in Juniperus excelsa subsp. excelsa (Cupressaceae)

This is a large scale investigation of morphological diversity in Juniperus excelsa excelsa. It offers complementary results to those obtained for the same populations using molecular markers. These two approaches are complementary and should be considered together in order to obtain a comprehensive view of the variability of J. excelsa excelsa.

Effect of geographic range discontinuity on species differentiation—East-Mediterranean Abies cilicica: a case study

In the present study, a genetic analysis of nuclear microsatellites was conducted in Abies cilicica populations growing in West Taurus, East Taurus, and Lebanon mountains to obtain evidence for significant genetic differentiation. Despite range fragmentation, all examined populations tended to maintain a relatively high level of genetic diversity (HE = 0.724) and showed moderate genetic differentiation (FST = 0.134) that is frequently noted in Mediterranean tree species. However, significant inbreeding, bottleneck effect, and low effective population sizes were detected, that may negatively affect species genetic resources. Bayesian clustering revealed three distinct groups, “West Taurus”, “East Taurus,” and “Lebanon”, which reflect geographic structure of the species natural range. Minor genetic admixture between Lebanese and East Taurus populations of A. cilicica was found, but no genetic admixture between Lebanese populations and West Taurus. We argue that significant genetic differentiation discovered among areas of species occurrence is probably due to the effect of long-lasting genetic isolation that started in that region along with the Pleistocene climatic alternation and was further enhanced with human-induced deforestations.

Identification and prioritization of areas with high environmental risk in Mediterranean coastal areas: A flexible approach

Interdisciplinarity and transdisciplinarity are the cornerstone for the future management of coastal ecosystems with many vulnerability and hazard indexes developed for this purpose, especially in the engineering literature, but with limited studies that considered ecological implications within a risk assessment. Similarly, the concept of prioritization of sites has been widely examined in biodiversity conservation studies, but only recently as an instrument for territory management. Considering coastal plant diversity at the species and community levels, and their vulnerability to three main potential hazards threatening coastal areas (oil spills, Hazardous and Noxious Substances pollution, fragmentation of natural habitats), the objective of this paper is to define an easy-to-use approach to locate and prioritize the areas more susceptible to those stressors, in order to have a practical instrument for risk management in the ordinary and extra-ordinary management of the coastline. The procedure has been applied at pilot areas in four Mediterranean countries (Italy, France, Lebanon and Tunisia). This approach can provide policy planners, decision makers and local communities an easy-to-use instrument able to facilitate the implementation of the ICZM (Integrated Coastal Zone Management) process in their territory.

Mapping post-glacial expansions: the peopling of Southwest Asia

Archaeological, palaeontological and geological evidence shows that post-glacial warming released human populations from their various climate-bound refugia. Yet specific connections between these refugia and the timing and routes of post-glacial migrations that ultimately established modern patterns of genetic variation remain elusive. Here, we use Y-chromosome markers combined with autosomal data to reconstruct population expansions from regional refugia in Southwest Asia. Populations from three regions in particular possess distinctive autosomal genetic signatures indicative of likely refugia: one, in the north, centered around the eastern coast of the Black Sea, the second, with a more Levantine focus, and the third in the southern Arabian Peninsula. Modern populations from these three regions carry the widest diversity and may indeed represent the most likely descendants of the populations responsible for the Neolithic cultures of Southwest Asia. We reveal the distinct and datable expansion routes of populations from these three refugia throughout Southwest Asia and into Europe and North Africa and discuss the possible correlations of these migrations to various cultural and climatic events evident in the archaeological record of the past 15,000 years.

Taxonomic differentiation of Cupressus sempervirens and C. atlantica based on morphometric evidence

We investigated the interspecific morphological relationships of two related Mediterranean Cupressus taxa and the possible geographic differentiation of Eastern Mediterranean C. sempervirens using morphometric analysis. A total of 446 individuals, representing eight C. atlantica (Morocco) and 10 C. sempervirens (Greece, Turkey and Lebanon) populations were examined. The 17 morphological characters of cone, seed and shoot with leaves were measured and analysed statistically. Significant morphological differences between C. atlantica and C. sempervirens were detected for the majority of analysed characters. For C. sempervirens, significant differences were also detected and these were related to its three regions of origin, the Greek Islands, Taurus Mts and Lebanon Mts. Multivariate analyses did not indicate a clear geographic pattern of differentiation in C. sempervirens populations. A relatively low level of phenotypic differentiation was detected between populations originating from the Greek Islands and Taurus Mts. We also observed a moderate multivariate differentiation between the Lebanese and remaining C. sempervirens populations. Phenotypic differentiation detected in the Asian part of the C. sempervirens range reflects patterns of differentiation similar to those described for other taxa occurring in the Taurus and Lebanon Mts.

Unlocking the Karyological and Cytogenetic Diversity of Iris from Lebanon: Oncocyclus Section Shows a Distinctive Profile and Relative Stasis during Its Continental Radiation

Despite being an important target of conservation concern and horticultural interest, Lebanese irises yet have a confusing taxonomic history and species’ delimitation is often considered problematic, more especially among royal irises (Iris section Oncocyclus). Indeed, these irises of exceptionally large and spectacular flowers have radiated across Caucasus and eastern Mediterranean giving rise to a number of strict endemic taxa, many of them being considered under threat. Whilst efforts have mostly focused on clarifying the evolutionary relationships in the group based on morphological and molecular data, karyological and cytogenetic characters have been comparatively overlooked. In this study, we established for the first time the physical mapping of 35S rDNA loci and heterochromatin, and obtained karyo-morphological data for ten Lebanese Iris species belonging to four sections (Iris, Limniris, Oncocyclus and Scorpiris). Our results evidenced distinctive genomic profiles for each one of the sections, where Oncocyclus irises, while having the lowest chromosome numbers, exhibit both the highest number of 35S loci and CMA3+ sites. The continental radiation of royal irises has been accompanied by a relative karyological and cytogenetic stasis, even though some changes were observed regarding karyotype formula and asymmetry indexes. In addition to that, our results enabled taxonomic differentiation between I. germanica and I. mesopotamica–two taxa currently considered as synonyms–and highlighted the need for further studies on populations of I. persica and I. wallasiae in the Eastern Mediterranean Region.