The major intention of the present study was to investigate whether an approach combining the use of niche-based palaeodistribution modeling and phylo-geography would support or modify hypotheses about the Quaternary distributional history derived from phylogeographic methods alone. Our study system comprised two closely related species of Alpine Primula. We used species distribution models based on the extant distribution of the species and last glacial maximum (LGM) climate models to predict the distribution of the two species during the LGM. Phylogeographic data were generated using amplified fragment length polymorphisms (AFLPs). In Primula hirsuta, models of past distribution and phylogeographic data are partly congruent and support the hypothesis of widespread nunatak survival in the Central Alps. Species distribution models (SDMs) allowed us to differentiate between alpine regions that harbor potential nunatak areas and regions that have been colonized from other areas. SDMs revealed that diversity is a good indicator for nunataks, while rarity is a good indicator for peripheral relict populations that were not source for the recolonization of the inner Alps. In P. daonensis, palaeo-distribution models and phylogeographic data are incongruent. Besides the uncertainty inherent to this type of modeling approach (e.g., relatively coarse 1-km grain size), disagreement of models and data may partly be caused by shifts of ecological niche in both species. Nevertheless, we demonstrate that the combination of palaeo-distribution modeling with phylogeographical approaches provides a more differentiated picture of the distributional history of species and partly supports (P. hirsuta) and partly modifies (P. daonensis and P. hirsuta) hypotheses of Quaternary distributional history. Some of the refugial area indicated by palaeodistribution models could not have been identified with phylogeographic data.

Our study highlights the complexity of climatic niche dynamics, and shows how conservatism and evolution have acted on different temporal scales and climatic parameters in Cedrela.

Primula sect. Auricula, a group of 25 species distributed in the European Alpine System, has been hypothesised to have diversified in the Quaternary through speciation in geographically isolated glacial refugia. We here examine whether the integrity of species is endangered through hybridisation upon contact in the Holocene. To do this, we (1) critically screened the literature for reported hybrids and supplemented this with our own knowledge of the group, (2) performed an admixture analysis of AFLP variation of two partly sympatric species pairs, P. hirsuta/P. daonensis and P. latifolia/P. marginata, and (3) analysed long-known hybrid populations of P. lutea 9 P. hirsuta in Wipptal/Austria to identify possible mechanisms of reproductive isolation. The literature survey revealed that populations of the 32 hybrid combinations known have been observed at 63 localities. In the admixture analysis, two admixed individuals per species were found among 524 individuals of P. latifolia and P. marginata, and 21 admixed individuals were found among 234 individuals of P. hirsuta. The analysis of P. lutea 9 P. hirsuta hybrids revealed that they show reduced pollen and seed fertility, and are limited to soils with intermediate pH values. We conclude that although species of P. sect. Auricula can readily be hybridised experimentally, hybridisation is rare in nature and species are stable. Mechanisms of reproductive isolation include geographical and ecogeographical isolation, ecological hybrid inviability and reduced hybrid fertility.

Aim We investigated the late Quaternary history of two closely related and partly sympatric species of Primula from the south‐western European Alps, P. marginata Curtis and P. latifolia Lapeyr., by combining phylogeographical and palaeodistribution modelling approaches. In particular, we were interested in whether the two approaches were congruent and identified the same glacial refugia. Location South‐western European Alps. Methods For the phylogeographical analysis we included 352 individuals from 28 populations of P. marginata and 172 individuals from 15 populations of P. latifolia and used amplified fragment length polymorphisms (AFLPs). For palaeodistribution modelling, species distribution models (SDMs) were based on extant species occurrences and then projected to climate models (CCSM, MIROC) of the Last Glacial Maximum (LGM), c. 21 ka. Results The locations of the modelled LGM refugia were supported by various indices of genetic variation. The refugia of the two species were largely geographically isolated, overlapping only 6–11% of the species' total LGM distribution. This overlap decreased when the position of the glacial ice sheet and the differential elevational and edaphic distributions of the two species were considered. Main conclusions The combination of phylogeography and palaeodistribution modelling proved useful in locating putative glacial refugia of the two alpine species of Primula. The phylogeographical data allowed us to identify those parts of the modelled LGM refugial area that were likely source areas for recolonization. The use of SDMs predicted LGM refugial areas substantially larger and geographically more divergent than could have been predicted by phylogeographical data alone.