The Geographical Projection of the Faunal Type Frequency Data

The faunal composition of formerly glaciated and therefore, nearly exclusively post-glacially re-populated Northern Europe is practically identical with NorthEastern Europe and Western Siberia which were considered as a main argument for being re-populated mostly from the East (Rebel 1931; de Lattin 1957, 1967). This major part of Europe clearly shows a high percentage of the "Siberian" faunal type in all mobile groups of animals such as birds (Stegmann 1932, 1938; Voous 1960, 1963) and butterflies (Reinig 1950; de Lattin 1964, 1967, see: Fig. 59, in Kostrowicki 1969; Fig. 1). This faunal type is also strongly represented in Central Europe, North of the Alps, being the prevailing faunal type mostly in the mountainous regions (e.g. Harz Mts., Bavarian and Bohemian forest, Sudetic Mts., etc.). In contrast, South of the large transversal chains of the Pyrenees, the Alps and the Northern Carpathians, the pre-dominance of the Mediterranean faunal type sensu lato has been demonstrated, with a decreasing gradient into Northern direction being extremely steep at the Pyrenees and partly North of the Alps and the Carpathians, but much more gently sloping from the Balkan peninsula to the Carpathian Basin. As a consequence of the overlapping of the different biogeo-graphical influences, there is a transitional belt in Southern Central Europe including a large part of the Carpathian Basin where the proportions of the different faunal types are rather balanced (de Lattin 1967; Varga and Gyulai 1978; Varga 1995, 2003b, 2006).

Several consequences follow from this general biogeographical setting of Europe.

• In Europe, the highest number of endemic species is confined to some, mostly mountainous parts of the Mediterranean peninsulas (e.g. Williams et al. 1999; Finnie et al. 2007). These areas, more or less, regularly overlap in the different taxonomical groups; thus they can be considered as hotspots for endemism, and at the same time, they were the main areas of survival during the Quaternary glaciations. These areas often show also a high level of "multi-species genetic divergence" (Petit et al. 2003).

• On the other hand, there are ecologically transitional regions with high numbers of species, but without a high proportion of endemism (Williams et al. 1999). These are characterised by an overlap of the ranges of species of different geographical origins caused by dispersal processes along gradients, e.g. the overlap of species belonging to different zonobiomes and azonal communities in the forest-steppe areas of the Carpathian Basin (Varga 1995). Recently, these areas have been identified as "melting pots" of genetic diversity (Petit et al. 2003) due to the secondary accumulation, re-distribution and re-combination of genotypes.

Another important observation was made by de Lattin (1957, 1964) who indirectly defined the "Siberian" species by their absence in the supposed Mediterranean refugial areas. These species show a peculiar "crowding" (de Lattins' "Stauungslinie") at the Northern boundary of the Mediterranean region. The re-interpretation of this biogeographical line subsequently followed in two steps. First, it was recognised that accumulated occurrence of marginal sub-species of continental species was shown around this line (Varga 1975, 1977), and later on, they were confirmed as multiple extra-Mediterranean refugia of continental species (Schmitt 2007; Schmitt et al. 2007) (Fig. 1).

Fig. 1 Important characteristics of biodiversity in Europe, compiled from various sources. Purple line: Southern and Western border of the high (>40%) representation of the Boreo-Continental (= Siberian) faunal elements (de Lattin 1967; Kostrowicki 1969). Blue line: Southern border of the expansion ("Stauungslinie") of the Boreo-Continental (= Siberian) faunal elements (de Lattin 1967). Red dots: important mountain arboreal refugia (compiled from different sources). Light blue circles: core areas of the multispecies genetic divergence of the 25 European forests. Full circles: divergence higher than average, empty circles: lower than average. Continuous lines indicate high divergence, dotted lines, intermediate divergence (re-drawn and simplified from Petit et al. 2003). Green circles: mean number of haplotypes per forest, averaged across species. Diversity is highest at relatively high latitudes, North of the three European peninsulas (re-drawn and simplified from Petit et al. 2003)

Fig. 1 Important characteristics of biodiversity in Europe, compiled from various sources. Purple line: Southern and Western border of the high (>40%) representation of the Boreo-Continental (= Siberian) faunal elements (de Lattin 1967; Kostrowicki 1969). Blue line: Southern border of the expansion ("Stauungslinie") of the Boreo-Continental (= Siberian) faunal elements (de Lattin 1967). Red dots: important mountain arboreal refugia (compiled from different sources). Light blue circles: core areas of the multispecies genetic divergence of the 25 European forests. Full circles: divergence higher than average, empty circles: lower than average. Continuous lines indicate high divergence, dotted lines, intermediate divergence (re-drawn and simplified from Petit et al. 2003). Green circles: mean number of haplotypes per forest, averaged across species. Diversity is highest at relatively high latitudes, North of the three European peninsulas (re-drawn and simplified from Petit et al. 2003)

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