Endemism patterns of the vascular flora of Lebanon: A dynamic checklist

TL;DR

This study compiles a checklist of 169 plant species unique to Lebanon, analyzing their diversity, distribution, and conservation status to highlight the country's role as a biodiversity hotspot.

Contribution

The paper provides a dynamic, taxonomically updated checklist of Lebanon's endemic vascular plants with conservation assessments and spatial distribution insights.

Findings

Lebanon's endemic flora includes 169 taxa across 37 families, with Asteraceae and Lamiaceae being the most represented.

Mount Lebanon and Anti-Lebanon host the highest number of exclusive endemic species, with 70 and 21 taxa respectively.

Over half of the endemic species are classified as Critically Endangered or Endangered according to IUCN standards.

Abstract

Given its high concentration of rare and endangered plant species, Lebanon is recognized as a biodiversity meso-hotspot within the Levant. This study presents a list of vascular plants endemic to Lebanon, detailing their taxonomic diversity, comparing them with the floras of Egypt, Iran and Turkey, and examining their life forms, spatial distribution across key geomorphological features, and conservation status. The list, comprising 169 taxa belonging to 37 families and 99 genera, was compiled through a comprehensive review of published literature, examination of herbarium specimens, and insights from field observations. The five most endemic-rich families are Asteraceae (18.9%), Lamiaceae (14.2%), Fabaceae (11.2%), Caryophyllaceae (5.9%), and Iridaceae (5.9%). The most endemic-rich genus is Astragalus (8.3%), followed by Centaurea (4.7%), Allium (4.1%), and Iris (3%). The comparison with other floras highlighted the relationships with the neighboring floristic regions, mostly the Irano-Turanian and Mediterranean. In terms of spatial distribution, Mount Lebanon and Anti-Lebanon emerge as centers of endemism, hosting respectively 70 and 21 exclusive taxa. Hemicryptophytes are the predominant life form (67.6%), followed by geophytes (13.6%), and chamaephytes (10%), reflecting the mountainous and Mediterranean character of Lebanon. According to IUCN Red List, 53% of the taxa have been assessed, with 10% taxa classified as Critically endangered, 27.8% as Endangered, 9.5% as Vulnerable. The checklist is available on an online repository and is considered dynamic. It will be updated in response to taxonomic changes resulting from genetic analyses and revisions of distribution ranges.

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