Phyteuma globulariifolium is a high alpine plant species growing in the European Alps and the Pyrenees. In order to elucidate its glacial history, 325 individuals from 69 populations were analysed using the amplified fragment length polymorphism (AFLP) technique. A strongly hierarchical phylogeographical pattern was detected: Two major east-west vicariant groups can be separated along a gap in the distributional area. A further subdivision into at least four populational groups is in congruence with presumed peripheral glacial refugia. There is no indication for survival on unglaciated mountain tops (nunataks) in the interior of the Pleistocene ice shield covering the Alps. Our results favour glacial survival in peripheral, unglaciated or not fully glaciated areas. Populations of P. globulariifolium in the Pyrenees are the result of relatively recent long-distance dispersal. Within the Alps, there is strong differentiation among groups of populations, whereas within them the differentiation is weak. This suggests high levels of gene-flow over short to middle distances.

The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.

Ranunculus glacialis ssp. glacialis is an arctic-alpine plant growing in central and southern European and Scandinavian mountain ranges and the European Arctic. In order to elucidate the taxon's migration history, we applied amplified fragment length polymorphism (AFLP) to populations from the Pyrenees, Tatra mountains and Northern Europe and included data from a previous study on Alpine accessions. Populations from the Alps and the Tatra mountains were genetically highly divergent and harboured many private AFLP fragments, indicating old vicariance. Whereas nearly all Alpine populations of R. glacialis were genetically highly variable, the Tatrean population showed only little variation. Our data suggest that the Pyrenees were colonized more recently than the separation of the Tatra from the Alps. Populations in Northern Europe, by contrast, were similar to those of the Eastern Alps but showed only little genetic variation. They harboured no private AFLP fragments and only a subset of East Alpine ones, and they exhibited no phylogeographical structure. It is very likely therefore that R. glacialis colonized Northern Europe in postglacial times from source populations in the Eastern Alps.

There is considerable controversy concerning the fate of Alpine plants during Pleistocene glaciations. While some studies have found evidence for nunatak survival, others have explained the present genetic patterns by survival only in peripheral refugia. We investigated 75 populations of high alpine Ranunculus glacialis from its entire Alpine distribution. Phylogeographical analyses of AFLP data revealed four groups of populations. Two of them, located in the western Alps, were genetically isolated from each other and from the eastern groups, whereas the two eastern Alpine groups were genetically more similar to each other. This suggests longer isolation and/or lower levels of gene flow in the two western groups. As all groups are close to, or overlap with, presumed glacial refugia, invoking glacial survival on nunataks is unnecessary to explain the present genetic pattern. Similar to the phylogeographical patterns of R. glacialis , the previously investigated alpine Phyteuma globulariifolium and Androsace alpina , which are also confined to siliceous bedrock, showed strong geographical affinities to peripheral refugial areas and there were large-scale congruencies in the location of these refugia for all three species.

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