ABSTRACT. The early Burdigalian (MN3) plant assemblage of the Güvem area (northwestern Central Anatolia) is preserved in lacustrine sediments of the Dereköy pyroclastics. Its age is well constrained by radiometric dates of basaltic rocks bracketing the pyroclastics, making the Güvem flora one of the extremely few precisely dated early Miocene floras in the Mediterranean region. The rich assemblage of impression fossils comprises ferns and fern allies (2 species), gymnosperms (12 spp.) and angiosperms (129 spp.). Ilex miodipyrena sp. nov. is described as a new fossil-species. The most diverse families in the assemblage are the Fagaceae with 12 taxa and the Fabaceae with 12 leaf morphotypes and one fruit taxon. Aquatic plants are represented by seven taxa, riparian (including palms) and swamp forest elements by >35 taxa, and lianas by three taxa (Smilax spp., Chaneya). The relatively large number of aquatic and riparian/swamp elements is congruent with the rich fish, amphibian and reptile record of the Güvem area. Another characteristic feature of the plant assemblage is the presence of various lobed leaves which show similarities with modern species of different families (e.g. Alangium, various Malvales). Trees and shrubs growing on well-drained soils and forming closed-canopy and open-canopy forests are the most diversified group (>70 taxa). In terms of number of specimens in the collection and based on field observations, by far the most abundant leaf fossils belong to evergreen oaks of Quercus drymeja and Q. mediterranea and to various types of foliage that cannot be assigned to a particular extant or extinct genus of Fagaceae. These sclerophyllous trees must have covered vast areas surrounding the wetlands that developed during the early Miocene in the Güvem Basin. Based on a recent reassessment of the ecology and taxonomic affinity of these trees, they are considered to reflect humid temperate climatic conditions but with a brief drier season during the winter months. These forests are more similar to the laurel forests of the southeastern United States and those stretching in a narrow belt south of the Himalayas to eastern central China. The large number of Fabaceae may indicate the presence of warm subtropical environments but this is difficult to assess, as they are known for having wide ecological ranges today and in the past. All in all, a larger part of the plant taxa point to forested vegetation. This is in agreement with previous palynological studies which detected only small amounts of herbaceous and grass pollen. Open patches of vegetation may have been restricted to river banks and to rocky areas in a volcanic landscape. The biogeographic patterns detected for the early Miocene of the Güvem assemblage are manifold; most taxa are widespread Northern Hemispheric elements. A substantial part of the species migrated from Asia into Europe during the (late) Paleogene and reached Anatolia during the early Miocene (Fagus, Paliurus, Chaneya, Ailanthus, Quercus kubinyii, Davallia haidingeri, Acer angustilo...
We developed a high quality reconstruction of May-June precipitation for the interior region of southwestern Turkey using regional tree-ring data calibrated with meteorological data from Burdur. In this study, three new climate sensitive black pine chronologies were built. In addition to new chronologies, four previously published black pine chronologies were used for the reconstruction. Two separate reconstructions were developed. The first reconstruction used all site chronologies over the common interval AD 1813-2004. The second reconstruction used four of the chronologies with a common interval AD 1692-2004. R² values of the reconstructions were 0.64 and 0.51 with RE values of 0.63 and 0.51, respectively. During the period AD 1692-1938, 41 dry and 48 wet events were found. Very dry years occurred in AD 1725, 1814, 1851, 1887, 1916, and 1923, while very wet years occurred in AD 1736, 1780, 1788, 1803, and 1892. The longest dry period was 16 years long between 1860 and 1875. We then explored relationships between the reconstructed rainfall patterns and major volcanic eruptions, and discovered that wetter than normal years occurred during or immediately after the years with the largest volcanic eruptions.
The new Smilax provides first fossil evidence of the Havanensis group and proves that this group had a western Eurasian distribution during the Miocene. The age of the fossils is in good agreement with the (molecular-based) purported split between the Havanensis and Hispida groups within Smilax. The Miocene Smilax provides evidence that all four subclades within the "New World clade" had a disjunct intercontinental distribution during parts of the Neogene involving trans-Atlantic crossings (via floating islands or the North Atlantic land bridge) and the Beringia land bridge.
spring East Atlantic/Western Russia (EA/WR) and North Sea Caspian patterns are likely key drivers of May-June precipitation in the Caucasus and Anatolia. NAO appeared to negatively affect rainfall low-frequency variability while effects of EA/WR were more apparent at the interannual timescales. We also show a potential positive effect of Black Sea surface temperatures on May-June precipitation. In the Caucasus, May-June represents the period of major water supply in semi-arid areas and the period with the highest potential of water scarcity in mesic areas. It is also a period of potential catastrophic flood events. Thus, changes to the precipitation regime during this season will be critical to both human and natural systems of the Caucasus region.
Abstract. The middle Miocene climate transition (MMCT) was a phase of global cooling
possibly linked to decreasing levels of atmospheric CO2. The MMCT
coincided with the European Mammal Faunal Zone MN6. From this time, important
biogeographic links between Anatolia and eastern Africa include the hominid
Kenyapithecus. Vertebrate fossils suggested mixed open and forested
landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer
the palaeoclimate during the MMCT and the succeeding cooling phase for a
middle Miocene (14.8–13.2 Ma) intramontane basin in southwestern Anatolia
using three palaeobotanical proxies: (i) Köppen signatures based on the
nearest living-relative principle; (ii) leaf physiognomy analysed with the
Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level
biogeographic affinities of fossil flora with modern regions.
The three proxies reject tropical and hot subtropical climates for the MMCT
of southwestern Anatolia and instead infer mild warm temperate
C climates.
Köppen signatures reject summer-dry Cs climates but cannot discriminate
between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on
the low X3.wet∕X3.dry ratio. Additionally, we assess whether the
palaeobotanical record resolves transitions from the warm Miocene
Climatic Optimum (MCO, 16.8–14.7 Ma) to the MMCT (14.7–13.9 Ma), and a
more pronounced cooling at 13.9–13.8 Ma, as reconstructed from benthic
stable isotope data. For southwestern Anatolia, we find that arboreal taxa
predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of
arboreal and non-arboreal elements strongly fluctuate, indicating higher
structural complexity of the vegetation. Our data show a distinct pollen
zone between MN6 and MN7+8 dominated by herbaceous taxa. The
boundary between MN6
and MN7+8, roughly corresponding to a first abrupt cooling at 13.9–13.8 Ma,
might be associated with this herb-rich pollen zone.
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