Genetic signals of ancient decline in Aleppo pine populations at the species’ southwestern margins in the Mediterranean Basin

Microsatellite markers were used to characterize the structure of genetic diversity in natural Moroccan Aleppo pine (Pinus halepensis Mill.) populations, the most southwesterly marginal populations of the species in the Mediterranean Basin. Twenty-two natural populations and one artificial population, located in four regions covering most of the natural range of P. halepensis in the country, were sampled. Across this range, towards the south and west (and towards high altitudes) the populations become increasingly discrete and discontinuous. The nuclear microsatellite marker analysis suggests that a large proportion of the Aleppo pines in Morocco have derived from a single genetic lineage, represented by a central group of 11 of the examined populations located in the High and Middle Atlas Mountains. In addition, two smaller groups, represented by the marginal southwestern High Atlas populations, and three still smaller north / northeastern groups of populations located in the Rif and northeast Middle Atlas Mountains, could be genetically distinguished. Further, coalescence analysis of historical demographic population patterns suggests that ancient bottlenecks occurred in all of the natural populations. However, the population differentiation and genetic diversity levels we found were good (Fst=15.47), presumably because of the species' good potential for long-distance dispersal of seeds and high invasive capacity, which appear to have maintained a state of stable near-equilibrium, meta-population dynamics since ancient times

Impact Of Climate Change On The Phytobiodiversity Of Tazekka National Park

The Tazekka National Park, created in 1950 on an initial area of 680 hectares, located in the mountain range of the Eastern, Middle Atlas, offers a great variety in terms of the landscape and the diversity of forest populations. However, studies have reported that the park’s biodiversity is threatened due to anthropogenic and climatic factors. The aim of this work is to carry out a comparative study concerning the influence of climate change during the years 1985, 2007 and 2018 on the distribution of plant species in different stations of the Tazekka National Park (Ras al ma, Bab Boudir, Bab Azhar and Jbel Tazekka).To carry out this work, several field trips were carried out. The results obtained in the form of GIS using the ArcGis 10.4.1 software have shown that climate change significantly influences the plant biodiversity of the Park. It is necessary to find assessment, monitoring and management strategies for these climate risks in order to preserve phytobiodiversity

The effects of temperature, hydric & saline stress on the germination of marram grass seeds (Ammophila arenaria L.) of the SIBE of Moulouya embouchure (Mediterranean -North-eastern Morocco)

ABSTRACT The seeds of Ammophila arenaria germinate in a wide range of temperatures ranging between 15 and 30°C with a low optimal temperature (20°C). The germination rate is maximal in the distilled water recalling the germination behavior of glycophytes. At the germination stage, marram grass seems to be much more sensitive to the saline stress than to the hydric stress. Indeed if this plant can tolerate polyethylene glycol concentrations reaching 150g/l it does not support sodium chloride concentrations higher or equal to 9g/l. Thus in the littoral dunes of the SIBE of the Moulouya embouchure, the germination of seeds would be controlled by the salinity of the substrate rather than by its osmotic forces