An approach to compare the environmental conditions of Acer in the Miocene and in the modern flora of Turkey, based on wood anatomy

Abstract In this study, xeromorphy ratios were calculated for Acer L. (maple) fossil woods in order to infer the precipitation conditions in the Miocene at the sites of the fossils, based on a comparison with the xeromorphy ratios of selected extant Acer species. The four studied petrified wood samples came from three localities of the Galatean Volcanic Province in Turkey: Kozyaka village (Bolu Province, Seben District), İnözü Valley (Ankara Province, Beypazarı District), and Kıraluç precinct between Nuhhoca and Dağşeyhler villages (Ankara Province, Beypazarı District). The calculated xeromorphy ratios ranged from 3 to 18 for the present-day wood and from 13 to 19 for the early Miocene wood. Values over 10 (11–18) represent xeric conditions; the lower values (3–7) indicate mesic conditions in modern Acer woods. The xeromorphy ratios of the Miocene wood indicate xeric conditions; we conclude that the sites of the fossil Acer woods were xeric, very similar to the modern Acer woodlands of central and southern Anatolia.