Continental and Marine Environmental Changes in Europe Induced by Global Climate Variability and Regional Paleogeography Changes

Pollen analysis of Miocene and Pliocene sediments from southeastern Europe and the northeastern Mediterranean is represented in pollen synthetic diagrams based on ecological criteria in order to clearly visualize changes in the composition and structure of the vegetation through time. New pollen data, together with abundant existing palynological information from this area, show a progressive reduction in plant diversity caused by a decrease in the most thermophilous and high-water requirement plants and, on the contrary, an increase in warm-temperate (mesothermic) and seasonal-adapted taxa during the Middle–Late Miocene and Pliocene. At the same time, an increase in high-elevation trees and herbs has been recorded, with a strong augmentation in Artemisia, first in the eastern Mediterranean and later on in the western Mediterranean area. This has been interpreted as a response of the vegetation to global and regional processes, including climate cooling related to the development of the East Antarctic Ice Sheet (EAIS), uplift of regional mountains during Alpine orogenesis and progressive movement of Eurasia towards northern latitudes as a result of the northwards collision of Africa. Pollen analyses dealing with Miocene–Pliocene sediments from the Paratethys are rare. Studies have focused on the Miocene and Pliocene palynology of the Central Paratethys (Petrescu et al. 1989a, b; Planderová 1990; Nagy 1991, 1992, 1999; Petrescu & Malan 1992) and Turkey (Benda 1971; Benda et al. 1975; Akgün & Akyol 1999), but the lack of any quantitative information render these analyses limited. However, palynological data, with reliable botanical identification, are available for the Miocene (Ivanov 1995; Ivanov & Koleva-Rekalova 1999; Palamarev & Ivanov 2001; Ivanov et al. 2002; Jiménez-Moreno et al. 2005) and the Pliocene (Drivaliari 1993; Drivaliari et al. 1999; Popescu 2001, 2002, 2006; Popescu et al. 2006a, b) of the same region. In these studies, pollen was not used for biostratigraphy but for climatic information, as independent biostratigraphic dating was available (see below). Pollen counts and a statistical treatment of the data were made to obtain reliable information about floral diversity, organization of the vegetation and to better visualize vegetation and climate change. The geographical position of the studied area, between Africa and Eurasia and between a Mediterranean and temperate climate, makes this region of great interest for palaeobotanic studies. Today, the southeastern part of the area is mainly occupied by steppe vegetation rich in Artemisia (i.e. the central Anatolian steppes), that is the main refuge area of thermophilous plants (mostly along the Turkish coastlines: Zohary 1973; Quézel & Médail 2003). Alpine tectonics were active during the Neogene, producing uplift of the Carpathians, Dinarides, Balkan, Rhodope and Taurides mountains. Then, important palaeogeographical changes occurred (see below; Rögl 1998; Meulenkamp & Sissingh 2003; Popov et al. 2004) that may have contributed to the pattern of vegetation distribution seen today. In this paper, we present a synthesis of palynological data, interpreted vegetation and climate dynamics based on Miocene and Pliocene deposits from Eastern Europe. New sections of Middle and Late Miocene age from this area have been analysed, adding new information to the already From: WILLIAMS, M., HAYWOOD, A. M., GREGORY, F. J. & SCHMIDT, D. N. (eds) Deep-Time Perspectives on Climate Change: Marrying the Signal from Computer Models and Biological Proxies. The Micropalaeontological Society, Special Publications. The Geological Society, London, 503–516. 1747-602X/07/$15.00 # The Micropalaeontological Society 2007. te l-0 03 50 11 6, v er si on 1 5 Ja n 20 09 published data. Changes in vegetation have been observed from the Langhian to the early Pliocene (16.3–3 Ma). These are mainly related to global climatic changes, in temperature and precipitation, that are linked to atmospheric and palaeogeographic changes that were of significant importance during the Neogene.