biodiversity of the baltic postglacial ecosystems: changes in time and space vytautas...

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)

Europeanhornbeam(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

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 structureGenetic divergenceHybrid zonesSpeciationSibling speciesIntraspecific systematics

Molecular ecology

• They all are questions of biodiversity

• Most intensive research conducted during last 15 years. Publications:

Molecular EcologyMolecular Biology and EvolutionMolecular Phylogenetics and EvolutionGeneticsMolekulyarnaya 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

ProtistaVermesMolluscaInsectaAvesMammalia

Molecular ecology in Lithuania

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!