Understanding population history for conservation purposes: population genetics of Saxifraga aizoides (Saxifragaceae) in the lowlands and lower mountains north of the Alps

Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations foun...

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Bibliographic Details
Published in:American Journal of Botany
Main Authors: Lutz, Eva, Schneller, J. Jakob, Holderegger, Rolf
Other Authors: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2000
Subjects:
Online Access:http://dx.doi.org/10.2307/2656602
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F2656602
http://onlinelibrary.wiley.com/wol1/doi/10.2307/2656602/fullpdf
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Summary:Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations founded by long‐distance dispersal after glaciation. A floristic survey of the historic and present distributions and an allozyme investigation were performed on one of these relic species, Saxifraga aizoides. The species was historically more abundant and had more stations in more regions of northeastern Switzerland. The former population structures within regions, nowadays destroyed, were still reflected in distinct and high regional genetic diversity and variation. There was weak evidence of increased inbreeding in outlying populations, but populations did not deviate from Hardy‐Weinberg equilibrium. No geographic pattern of genetic variation above the regional scale (>10 km) was found. Based on the spatial and genetic structures found, it was not possible to discriminate between the abovementioned hypotheses. Nevertheless, the study shows how a thorough evaluation of distribution and abundance data aids the interpretation of genetic data with respect to population history, biogeography, and conservation biology.