Biodiversity of the Baltic postglacial ecosystems: CHANGES IN TIME AND SPACE Vytautas Kontrimavičius Lithuanian Academy of Sciences

Pleistocene glaciations in the northern hemisphere The gray areas represent ice shields

Approximate appearance of Bering Land Bridge during late Pleistocene time (after Rausch, 1994) The dotted areas – ice The white areas – land

Eastern Palearctic Biodiversity Ecosystems of the Eastern Palearctic –have not been covered with Pleistocene glaciations –therefore their biodiversity is much higher than biodiversity of the Western Palearctic (including European) ecosystems

Western Palearctic Biodiversity Postglacial ecosystems of Western Palearctic –are relatively species-poor –are formed continuously up to now due to natural expansion of species ranges anthropogenic transfer

Baltic Biodiversity Feature of ecosystems of the Baltic region: –south-western distribution limit of northern and Siberian species of Taiga and Tundra biomes –north-eastern distribution limit of Western- European species of deciduous forest biome

The tundra birch (Betula nana) European hornbeam (Carpinus betulus)

Cloudberry (Rubus chamaemorus) Mistletoe (Viscum album)

Mountain hare (Lepus timidus) Fat dormouse (Glis glis)

Pond turtle (Emys orbicularis) Whitefish: Coregonus lavaretus Coregonus albula Tree frog (Hyla arborea)

Baltic Biodiversity Combination of northern and southern species in ecosystems –increases their stability in variable seasonal climate however –may cause large-scale changes (extinctions, migrations) in case of long-term climate change

Baltic Biodiversity Molecular methods in ecology provided the new possibilities: –study of ecosystem structure –study of population structure within species They revealed the genetic heterogeneity of populations in the Baltic region

Microtus agrestis sampling sites Southern Western Eastern

Microtus agrestis postglacial expansion

Microtus agrestis similarity of populations Southern Western Eastern Lithuania

The listed data on the population structure of the Baltic region seem to be the only available up to now. Therefore, the Baltic region of Europe remains one of the least researched in the aspect of phylogeography Baltic Biodiversity

The latest data –disprove the hypothesis of Hewitt (1999) that the postglacial biota of Europe has been mainly formed by the populations of the southern refugia –reveal that the northern Europe, including the Baltic region, has been colonized by migration from remote eastern populations of southern Siberia Baltic Biodiversity

The questions solved by the molecular ecology: Population structure Genetic divergence Hybrid zones Speciation Sibling species Intraspecific systematics Molecular ecology They all are questions of biodiversity

Most intensive research conducted during last 15 years. Publications: Molecular Ecology Molecular Biology and Evolution Molecular Phylogenetics and Evolution Genetics Molekulyarnaya Biologiya etc. Molecular ecology

In Lithuania, there were little possibilities to conduct molecular ecology research due to economic reasons, however, recently Molecular ecology

a laboratory of molecular ecology has been equipped in the Institute of Ecology of Vilnius University a field material has been collected for the phylogeographic studies of Protista Vermes Mollusca Insecta Aves Mammalia Molecular ecology in Lithuania

The main research trends: structure of populations intra-specific hybrid zones significance of the European and Siberian refugia in the formation of post-glacial biota of Northern Europe

Thank you for attention!