Types of oreal and oreotundral disjunctions in the western Palearctic

Abstract

The cyclic changes of the Pleistocene between cold and warm periods resulted in antagonistic responses within two different groups of organisms: one expanding during the warm periods and retracting during the cold phases and another with opposed responses. The latter group is composed of so-called arctic and alpine species. These species have recently become the focus of phylogeographical research. However, we still lack a comprehensive characterization of the different types of alpine and arctic-alpine disjunctions in the western Palearctic. Such an overview might facilitate the selection of different model species to test the different patterns of disjunctions for congruences revealing their past distribution. Therefore, we list all alpine and arctic-alpine disjunction types of the western Palearctic using butterflies and moths as a model group. We distinguish between (1) endemics of the Alps (a) with strongly restricted and (b) with broader distributions; (2) alpine disjunct species (a) with perialpine disjunctions and (b) with a wide western Palearctic distribution; (3) oro-Mediterranean species; and (4) arctic-alpine disjunct species. These types of distributions and further subtypes are exemplified using chorological data of butterfly and moth species. In this context, we discuss the intraspecific differentiation and the differentiation among siblingspecies within and among disjunct parts of the distribution area. We also formulate hypotheses of the distribution patterns during the last ice age which might best explain the actual patterns. Finally, we suggest some case studies of genetic analyses to test the above mentioned hypotheses.

Butterfly Diversity in a Changing Scenario

“…As concerns their distributions, narrow-range species were strongly influenced by Pleistocene glaciations, both in the case of plants (Tribsch, 2004) and of some invertebrates, including butterflies (Hüemer, 1998). Since the Alps are the largest and highest mountain system in Europe, it is not surprising that a high number of endemic species, typical of the mountain environments, is found here, as observed in many Lepidoptera and especially in micro-moths (Varga & Schmitt, 2008). Some of these endemic species are distributed throughout the Alps, while others are local endemism found only in parts of them.…”

“…Two types of local hotspots of endemism have been identified. The first group includes species whose ranges are restricted to peripheral regions of the Alps and mainly confined to the intermediate and low altitudes, as observed in some species of the genus Erebia and in some Lyceanids (Varga & Schmitt, 2008). The highest concentrations of these local endemics are found in the southwestern and southeastern regions of the Alps, which include large areas at low altitude, not covered by ice during glaciations.…”

“…The second group is represented by species confined to the inner parts of the Alps, such as a large number of micro-moths (Hüemer, 1998) and some butterfly species (i.e. Erebia nivalis) (Varga & Schmitt, 2008). These species are generally restricted to high mountain habitats and might have survived glaciations in small ice-free areas, on the slopes of the inner Alpine mountains (Schmitt, 2009).…”

Butterfly diversity and biogeography on the Croatian karst mountain Biokovo: Vertical distribution and preference for altitude and aspect?

“…Gutiérrez, 1997;Liška & Skyva, 1997;Wettstein & Schmid, 1999;Beneš et al, 2000;Varga, 2003aVarga, , b, 2008. Species diversity varies spatially, displaying latitudinal and longitudinal gradients and there are core areas that serve as centres of dispersal and restricted territories where endemic species accumulate (Varga, 1995;Varga & Schmitt, 2008).…”

Allopatric cryptic diversity in the alpine species complex Phtheochroa frigidana s. lat. (Lepidoptera: Tortricidae)

“…The evolution of several alpine species is likely to be explained by climatic changes during the Pleistocene (Varga & Schmitt 2008). Cyclic changes in temperature caused up-and down-range shifts and the disruption of formerly connected populations.…”