Endemism

Endemism is based on the principle that a species is restricted to a defined geographic location, habitat type, or specific island and does not occur naturally outside that area.^【1】 Endemic species, of critical importance in plant taxonomy and plant geography, provide fundamental scientific data for understanding habitat fragmentation, historical migration routes, and the origins of floras.

Endemic Taxa and Evolutionary Classification

Endemic plants are primarily classified into two main groups according to their formation processes and historical histories:

• Paleoendemics (conservative or relict endemics): Species that once had wide distributions during ancient geological periods but now survive only in specific refuge areas (refugium) due to climatic changes. These taxa are “living fossils” in systematic terms, often isolated with no close relatives or representing monotypic genera.
• Neoendemics: Taxa that have recently evolved through evolutionary processes and remain confined to a narrow area because they have not yet spread beyond their origin.

At the taxonomic scale, species and supraspecific taxa are defined as "megaendemic", while infraspecific taxa (subspecies and varieties) are termed "microendemic". It is generally accepted that the majority of microendemics are dynamic neoendemics with dispersal tendencies.

A more detailed classification based on cytotaxonomic findings identifies three types: schizoendemic, patroendemic, and apoendemic. Schizoendemics are related taxa that originated from a widely distributed ancestral taxon through geographic isolation in different regions. Patroendemics are limited-range ancestral taxa that are diploid and give rise to new polyploid species in neighboring areas. Apoendemics are terminal endemic taxa that arose directly from an ancestral taxon through polyploidy (instantaneous speciation).^【2】

Edaphic and Geomorphological Endemism Factors

One of the most fundamental factors determining endemism rates in a region is geological and topographic isolation. There is a direct correlation between rock composition and endemism. Ultramafic (serpentine) rocks, rich in heavy metals (magnesium, iron, chromium, nickel) but poor in nutrients, create conditions for a special phenomenon known as "edaphic endemism". Plant populations growing on these substrates undergo physiological and morphological differentiation, developing the characteristic known as "serpentinomorphism", and this geological isolation triggers the formation of new species. Additionally, limestone rocks and slope debris provide suitable habitats for the conservation of relict endemics.

Endemism(Generated by Artificial Intelligence)

Endemism and Distribution Analysis of the Flora of Türkiye

Türkiye exhibits remarkable endemism richness globally due to its geographic position at the intersection of three distinct phytogeographic regions, its mountainous topography, and its lesser exposure to Quaternary glaciations compared to Europe. Of the approximately 10,000 taxa in the country’s flora, more than 3,000 (about 33.5 percent) are endemic. This proportion is comparable to the total plant diversity of the entire European continent. In the distribution of endemic species in Türkiye, the "Anatolian Diagonal"—a line extending from the Amanos Mountains to Northeastern Anatolia—acts as a major geographic barrier, creating ecological and geological isolation that promotes speciation.

Regionally, the highest endemism rates are found in the Mediterranean region, followed by Eastern Anatolia.

At the family level, Asteraceae (daisies) and at the genus level, Astragalus (milkvetches), are the groups with the highest number of endemic species.^【3】 For example, in localized areas such as the İzmir region, endemism rates are below the national average, at approximately 8.49 percent. Endemic density in this area increases with elevation and is concentrated in the subalpine zones of the Nif and Manisa mountains. Although the majority of Türkiye’s endemics are considered Quaternary-origin neoendemics, a significant number of paleoendemic taxa dating back to the Tertiary period continue to persist in the flora.^【4】