Patterns of Endemism in Turkey, the Meeting Point of Three Global Biodiversity Hotspots, Based on Three Diverse Families of Vascular Plants

Jalil Noroozi,Gerald M Schneeweiss,Golshan Zare,Zahra Asgarpour,Mahbubeh Sherafati,Mohammad Mahmoodi,Dietmar Moser

doi:10.3389/fevo.2019.00159

Abstract

Centres of endemism and areas of endemism are important biogeographic concepts with high relevance for conservation and evolutionary biology. Turkey is located at the intersection of three global biodiversity hotspots (Mediterranean, Caucasus, Irano-Anatolian) and harbors remarkable levels of plant diversity and endemism. Nevertheless, hotspots of vascular plant endemics have never been identified using formal quantitative approaches in this diverse region. Here, using data on 1102 endemic taxa of three species-rich families (Asteraceae, Lamiaceae, Boraginaceae) we identified (i) centres of endemism based on three well established indices (endemic richness, range-restricted endemic richness and weighted endemic richness) and (ii) areas of endemism using Endemicity Analysis. A total of 14 grid cells belonging to centres of endemism are identified as hotspots by at least one of the indices. Areas of endemism were identified in south-western Turkey (West-Taurus), southern and central Anatolia (Anatolian Diagonal), in north-eastern Turkey (Pontic-Ala), and in south-eastern Turkey (Hakkari). All hotspots of plant endemism in Turkey included high mountains, which are severely threatened by anthropogenic activities. Although the identified centres of endemism cover only 16% of surface area of Turkey they harbour 59% of the endemic taxa, emphasizing their conservation priority. As the majority of the endemic taxa of Turkey are local endemics and narrowly distributed, protection of the identified hotspots would allow a high proportion of likely threatened species to be protected.

Highlights

Endemism, i.e., the restriction of a taxon to a geographic place, is one of the central concepts in biogeography (Anderson, 1994), which has been widely used to define floristic units (Rivas-Martínez et al, 1997)
We address the following questions: (1) Where are the Center of Endemism (CE) and Area of Endemism (AE) in Turkey? (2) Are these exclusively inside global biodiversity hotspots? (3) Are these congruent with chorological patterns or hotspots identified in previous phytogeographical studies? (4) Is there a relation between topographical heterogeneity and endemic richness as suggested for other areas (Irl et al, 2015; Noroozi et al, 2018)?
The endemic richness of cells ranges from 1 to 129, the value of the highest endemic richness overall corresponding to the western Taurus (Figure 2A)

Summary

Introduction

I.e., the restriction of a taxon to a geographic place (irrespective of taxonomic and geographic scale), is one of the central concepts in biogeography (Anderson, 1994), which has been widely used to define floristic units (Rivas-Martínez et al, 1997). Areas of endemism (AEs) are fundamental entities of analyses in biogeography (Morrone, 2008) They are defined as areas that are rich in endemics, but whose species have congruent distributions (Morrone and Crisci, 1995; Linder, 2001; Bradshaw et al, 2015). Biogeographers and evolutionary biologists focus on explaining the causes for the occurrence of AEs (Nelson and Platnick, 1981; Major, 1988; Anderson, 1994). Both CEs and AEs are very important in conservation biology, they are little investigated even in well-known global biodiversity hotspots

Methods

Results

Discussion

Conclusion