Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections

RESEARCH ARTICLE Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections Dilsad DagtekinID1☯¤*, Evrim A. Şahan1☯, Thomas Denk2‡, Nesibe Ko¨ se3‡, H. Nu¨ zhet Dalfes1‡ 1 Eurasia Institute of Earth Sciences, Istanbul Technical University, Istanbul, Turkey, 2 Department of Paleobiology, Swedish Museum of Natural History, Stockholm, Sweden, 3 Department of Forest Botany, Faculty of Forestry, Istanbul University-Cerrahpasa, Istanbul, Turkey ☯ These authors contributed equally to this work. ¤ Current address: Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland ‡ These authors also contributed equally to this work. * dilsad.dagtekin@ieu.uzh.ch Abstract Species distribution models can help predicting range shifts under climate change. The aim of this study is to investigate the late Quaternary distribution of Oriental beech (Fagus orien- talis) and to project future distribution ranges under different climate change scenarios using a combined palaeobotanical, phylogeographic, and modelling approach. Five species distri- bution modelling algorithms under the R-package ‘biomod2‘were applied to occurrence data of Fagus orientalis to predict distributions under present, past (Last Glacial Maximum, 21 ka, Mid-Holocene, 6 ka), and future climatic conditions with different scenarios obtained from MIROC-ESM and CCSM4 global climate models. Distribution models were compared to palaeobotanical and phylogeographic evidence. Pollen data indicate northern Turkey and

the western Caucasus as refugia for Oriental beech during the Last Glacial Maximum. Although pollen records are missing, molecular data point to Last Glacial Maximum refugia in northern Iran. For the mid-Holocene, pollen data support the presence of beech in the study region. Species distribution models predicted present and Last Glacial Maximum dis- tribution of Fagus orientalis moderately well yet underestimated mid-Holocene ranges. Future projections under various climate scenarios indicate northern Iran and the Caucasus region as major refugia for Oriental beech. Combining palaeobotanical, phylogeographic and modelling approaches is useful when making projections about distributions of plants. Palaeobotanical and molecular evidence reject some of the model projections. Neverthe- less, the projected range reduction in the Caucasus region and northern Iran highlights their importance as long-term refugia, possibly related to higher humidity, stronger environmental and climatic heterogeneity and strong vertical zonation of the forest vegetation. PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0242280 November 17, 2020 1 / 19 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Dagtekin D, Şahan EA, Denk T, Ko¨se N, Dalfes HN (2020) Past, present and future distributions of Oriental beech (Fagus orientalis) under climate change projections. PLoS ONE 15 (11): e0242280. https://doi.org/10.1371/journal. pone.0242280 Editor: Michal Bosela, Technical University in Zvolen, SLOVAKIA Received: June 9, 2020 Accepted: October 29, 2020

Published: November 17, 2020 Copyright: © 2020 Dagtekin et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: Part of our data is open-source and available to everyone online (http://www.euforgen.org/species/fagus-orientalis/ ), and part of our data belongs to the General Directory of Forestry, Turkey. That is why, we are not allowed to distribute the data ourselves, yet, it is available upon request to the General Directory of Forestry, Turkey. Here is the contact information: Republic of Turkey, General Directorate of Forestry Address: Beştepe Mahallesi So¨ğu¨to¨zu¨ Caddesi No:8/1 06560 Yenimahalle / ANKARA / TURKEY Phone: +90 312 296 40 00