Past, present, and future geographic range of an oro-Mediterranean Tertiary relict: The juniperus drupacea case study

Łukasz Walas,Angel Romo,Magda Bou Dagher-Kharrat,Jean Stephan,Karolina Sobierajska,Tolga Ok,Ali A Dönmez,Adam Boratyński,Anna K Jasińska,Bouchra Douaihy,Salih S Kanoğlu

doi:10.1007/s10113-019-01489-5

Abstract

Juniperus drupacea is a unique relict species found in the mountains of southern Greece, southern Turkey, and western Syria and Lebanon. The aim of this study was to describe the natural range of this juniper by determining the current locations of its populations and to predict a theoretical range for the species based on current, past, and future climatic conditions. We used data from the literature, herbarium materials, and our unpublished field notes (about 500 georeferenced points in total) to determine the current natural distribution of J. drupacea (realized niche). To predict suitable conditions with the program MaxEnt, we used data from the WordClim database, which allowed estimation of the potential niche. The potential niche of J. drupacea was much wider during the Last Glacial Maximum (LGM) and was severely restricted during the Eemian interglacial period. Depending on the climate scenario, this species could become endangered in the future due to climate changes. Considering the relatively restricted geographic range of J. drupacea and the decreasing numbers of localities where it is found, conservation strategies should be adopted to allow for preservation of its genetic and morphological diversity.

Highlights

The Syrian juniper (Juniperus drupacea Labill.) is a Tertiary relict (Palamarev 1989) that currently occurs in a restricted area (Browicz 1982)
This feature was the motivation for placing J. drupacea in its own genus Arceuthos Antoine & Kotschy; this is generally treated as a synonym of Juniperus L. (Coode and Cullen 1965; Gaussen 1968; Christensen 1997; Farjon 2005; Adams 2014)
During the late Tertiary and early Quaternary, it was probably a component of the Tethyan and, subsequently, the Mediterranean sclerophyll flora (Palamarev 1989; Kvaček 2002; Palamarev et al 2005); its palaeo-remnants are very scarce (Stockey et al 2005). It was affected by relatively high temperatures and water deficits during the Messinian salt crisis, and afterward, during the Pliocene and Pleistocene, exposed to climate cooling and oscillations in temperature, which reduced its geographic range to the current area

Summary

Introduction

The Syrian juniper (Juniperus drupacea Labill.) is a Tertiary relict (Palamarev 1989) that currently occurs in a restricted area (Browicz 1982). During the late Tertiary and early Quaternary, it was probably a component of the Tethyan and, subsequently, the Mediterranean sclerophyll flora (Palamarev 1989; Kvaček 2002; Palamarev et al 2005); its palaeo-remnants are very scarce (Stockey et al 2005) It was affected by relatively high temperatures and water deficits during the Messinian salt crisis, and afterward, during the Pliocene and Pleistocene, exposed to climate cooling and oscillations in temperature, which reduced its geographic range to the current area

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Conclusion