Ricerc@Sapienza

Lake Ohrid (Albania/FYROM) is the oldest continuously existing lake in Europe. It is located in a graben formed during the last phases of Alpine orogenesis the north-eastern Mediterranean region at 693 m a.s.l. It is included in the UNESCO “World Heritage Site” list since 1979 and represents an important hotspot of biodiversity, as it hosts over two hundred endemic species. A recent drilling campaign realized in spring 2013, mostly financed by the ICDP (International Continental Scientific Drilling Program) was carried out in the frame of the project SCOPSCO (Scientific Collaboration On Past Speciation Conditions in Lake Ohrid).
Palynological analyses were carried out in a composite sequence (DEEP) 569 m long and more than 1.2 million years old drilled in the depocenter of the lake. Pollen analysis (one sample every ca. 1600 years) of the top 200 m of the sequence and covering the last 500,000 years (at least five glacial/interglacial cycles), shows alternations between forested and non-forested periods in conjunction with a progressive change from cooler/wetter to warmer/drier conditions during interglacial and glacial periods [1]. Here we present the high resolution (roughly one sample every 400 years) pollen results of sediments ascribed to the last interglacial complex (LIG, 130-70 ka) the terrestrial equivalent of MIS5. The LIG, including the Eemian, the Last Interglacial (LI, MIS5e) and the early Glacial (MIS5d- a) is investigate to reconstruct past climate parameters and hypothesize future scenarios and risks. The Eemian (MIS5e) has been multidisciplinary investigated and its chronology carefully tuned using tephra layers and sinchronization with other proxies [2].The so far obtained results indicate a fairly good conservation of pollen and resulting in a certain taxonomic variety (95 different taxa). Pollen concentration is between 13,000 and 395,000 grains/ g. The average counts are over 500 pollen grains per sample. The AP (arboreal pollen) % curves from Ohrid are similar to those of two other lakes [3]. There are, however, minor differences. In all three diagrams we can distinguish the Eemian and its beginning around 130 ka. Also interstadials and stadials included in MIS 5 and defined in La Gran Pile (France) record since 1978 [4] are clear in the Ohrid record: Me?lisey I, St. Germain I (divided in Ia and Ic), the Me?lisey II and St. Germain II. This last appears to be tripartite at Ohrid, similarly to what happens at Ioannina [5], and in Italy at Lago di Vico [6] and at Lagaccione [7].