Caractérisation écologique des peuplements de Juniperus excelsa au Liban

Juniperus excelsa is the second most widespread conifer tree in Lebanon. It grows in sites where no other conifer can survive. Despite its high ecological value, until now no field study was made in order to characterize these woodlands in Lebanon. We gathered data on the density, size structure, regeneration rate, cone production, proportion of filled seeds (using radiography) and spatial structure. The study was based on the monitoring of eight plots located in contrasted bioclimatic zones in Lebanon. We showed that the overall density of the Lebanese stands of J. excelsa is low and does not exceed 257 trees/ha. Moreover, the regeneration rate of these stands is lower than one and the percentage of filled seeds does not exceed 40%. The main threat affecting the survival of the Lebanese populations differs among sites including woodcutting, expansion of agricultural lands, overgrazing and the coupling with the hydric stress. This makes the future of the Juniper woodland in Lebanon largely uncertain.
Juniperus excelsa pousse dans des sites où aucun autre conifère ne survit et souffre d’une forte pression anthropique. Il est cependant le second
Cheikha Douaihy Bouchra, Restoux Gwendal, Machon Nathalie, Bou Dagher-Kharrat Magda. Ecological characterization of the Juniperus excelsa stands in Lebanon. In: Ecologia mediterranea, tome 39 n°1, 2013. Actes du IVe Colloque international sur le Genévrier thurifère. 5-8 octobre 2011 Mont-Dauphin et Saint-Crépin (Hautes-Alpes, France) pp. 169-180.