Mitochondrial phylogeography of the European ground squirrel, Spermophilus citellus, yields evidence on refugia for steppic taxa in the southern Balkans

Abstract

The spatial genetic structure of the European ground squirrel, a species characteristic of the short-grass steppe, was investigated on the basis of a 1140-bp cyt b gene sequence. The phylogeographical architecture of this species is expected to shed light on the putative long-term presence of the steppic ecosystem in south-eastern Europe and the evolutionary consequences of glacial cycles as forcing factors in speciation. Among 31 haplotypes, three highly divergent phylogenetic lineages (Southern, Northern and Jakupica) were recognized. This result suggests the past existence of an allopatric fragmentation event caused by effective biogeographical barriers. The Southern lineage consisted of the southernmost populations, those from Greece, Macedonia and European Turkey, and showed the highest divergence from all other samples. Haplotypes of the Northern lineage showed little geographical structure, with dispersal on both sides of the Danube River and in both of the two main geographical fragments of the species. The Jakupica lineage is a geographical isolate on a high plateau in central Macedonia. The estimated time for divergence of the Southern lineage (ca. 0.58 Mya) suggests the long-term persistence of a short-grass steppic refugium in the southern Balkans. Although the divergence between the Northern and Jakupica lineages occurred more recently (ca. 0.3 Mya), it still putatively predates two glacial cycles. The three phylogeographical lineages of the European ground squirrel should be regarded as independent units for conservation management purposes.

Mitochondrial cytochrome b sequences resolve the taxonomy of field mice (Apodemus) in the western Balkan refugium

“…Bilton et al (1998) emphasized the importance of Mediterranean refugia as sites of endemism rather than a source of south-to-north oriented postglacial recolonization routes. Studies on mammals with restricted dispersal did retrieve phylogeographic lineages endemic to small areas of the Balkan peninsula, therefore providing evidence of the refugia within a refugium (Kryštufek et al 2007(Kryštufek et al , 2009Buzan et al 2010). The situation regarding field mice was evidently a different one.…”

Site selection of European ground squirrels (Spermophilus citellus) in Eastern Romania and how they are influenced by climate, relief, and vegetation

“…Dating back to the Middle Pleistocene, the European ground squirrel shows three highly divergent phylogenetic lineages that are all under conservation concerns due to their declining trends (Kryštufek et al, 2009). Depending on the local environmental conditions, the European ground squirrel distribution could be influenced by specific limiting factors in different parts of its range (Koshev and Kocheva, 2007).…”

Conservation genetics of xerothermic beetles in Europe: the case of Centricnemus leucogrammus

“…Considering the dramatic loss of xerothermic habitats as a consequence of changes in land use taking place particularly in central and western Europe (Michalik and Zarzycki 1995;Mazur and Kubisz 2000;Varga 2001), but also in eastern Europe (Cremene et al 2005), the evaluation of genetic variation and phylogeographical patterns in xerothermic species is of immediate importance if appropriate conservation measures are to be undertaken. Although knowledge of the genetic diversity, phylogeography and population genetics of steppe plants (Franzke et al 2004;Szczepaniak and Cieślak 2006;Szczepaniak et al 2007;Schlee et al 2007;Wróblewska 2008) and vertebrates, mainly rodents (Biedrzycka and Konopiński 2008;Banaszek et al 2009;Kryštufek et al 2009), has increased significantly in the last years, information concerning invertebrate populations are scarce and limited mostly to semi-xerothermophilous butterflies (Schmitt and Hewitt 2004;Gratton et al 2008) and snails (Pfenninger and Posada 2002).…”