Biodiversity of the Baltic postglacial ecosystems: CHANGES IN TIME AND SPACE

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

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

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

4. 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

5. 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

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

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

8. Cloudberry (Rubus chamaemorus) Mistletoe (Viscum album)

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

10. Pond turtle (Emys orbicularis) Tree frog (Hylaarborea) Whitefish: Coregonus lavaretus Coregonus albula

11. 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

12. 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

16. Southern Western Eastern Microtus agrestis sampling sites

17. Microtus agrestis postglacial expansion

18. Lithuania Eastern Lithuania Western Southern Microtus agrestis similarity of populations

20. Baltic Biodiversity • 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

21. 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

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

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

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

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

26. 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

27. Thank you for attention!