Data from: Conservation phylogeography: does historical diversity contribute to regional vulnerability in European tree frogs (Hyla arborea)

Documenting and preserving the genetic diversity of populations, which
conditions their long-term survival, has become a major issue in
conservation biology. The loss of diversity often documented in declining
populations is usually assumed to result from human disturbances; however,
historical biogeographic events, otherwise known to strongly impact
diversity, are rarely considered in this context. We apply a multi-locus
phylogeographic study to investigate the late-Quaternary history of a tree
frog (Hyla arborea) with declining populations in the northern and western
part of its distribution range. Mitochondrial and nuclear polymorphisms
reveal high genetic diversity in the Balkan Peninsula, with a spatial
structure molded by the last glaciations. While two of the main refugial
lineages remained limited to the Balkans (Adriatic coast, southern
Balkans), a third one expanded to recolonize Northern and Western Europe,
loosing much of its diversity in the process. Our findings show that
mobile and a priori homogeneous taxa may also display substructure within
glacial refugia (“refugia within refugia”), and emphasize the importance
of the Balkans as a major European biodiversity center. Moreover, the
distribution of diversity roughly coincides with regional conservation
situations, consistent with the idea that historically impoverished
genetic diversity may interact with anthropogenic disturbances, and
increase the vulnerability of populations. Phylogeographic models seem
important to fully appreciate the risks of local declines and inform
conservation strategies.