High genetic and morphological diversity despite range contraction in the diploid Hieracium eriophorum (Asteraceae) endemic to the coastal sand dunes of south-west France

Abstract

Endemic plants inhabiting coastal sand dunes show augmented extinction risks due to the dynamic nature of dunes and strong human pressure on coastal areas. To investigate the survival strategies and threats to long-term survival of such species, we combined genetic, morphological and biogeographical approaches, using the example of Hieracium eriophorum (Asteraceae) and its putative cryptic sister species H. prostratum, which are endemic to the longest coastal sand dune in Europe. An analysis of amplified fragment length polymorphism revealed high within-population genetic variability, and slight isolation by distance was the only indication of genetic population structure. Thus, no signs of genetic threats to survival were found. Furthermore, genetic and morphometric data provided no evidence for the existence of two species. Therefore, we propose to synonymize H. prostratum with H. eriophorum and provide a nomenclatural overview with typification. Finally, an analysis of historical distribution records showed that, during the last 100 years, the species was lost from its range margins, where its habitat became fragmented. Taken together, our results suggest that one successful survival strategy of narrow endemics may be the achievement of large local population sizes on a small geographical scale, thus avoiding the genetic problems inherent to small and fragmented populations. Dune management policies should thus take care that the current tendencies to allow more erosion will not result in too severe fragmentation of the remaining continuous stretches of dune habitat.

Parallel declines in species and genetic diversity driven by anthropogenic disturbance: a multispecies approach in a French Atlantic dune system

“…Historical data suggest a larger and a more continuous distribution of endemics such as Alyssum loiseleurii, Astragalus baionensis, and Hieracium eriophorum during the 19th century until the first half of the 20th century, when increased waterside development started (e.g., Loiseleur–Deslongchamps ; Lloyd and Foucaud ; Jeanjean ; Frey et al. ,b).…”

“…() and Frey et al. () using two to three primer pairs (Table S2) per species [note that the AFLP dataset of H. eriophorum was from Frey et al. ()].…”

“…() using two to three primer pairs (Table S2) per species [note that the AFLP dataset of H. eriophorum was from Frey et al. ()]. The complete protocol (from DNA extraction to genotyping) was replicated for 15% of the specimens to assess the reproducibility of the results (Bonin et al.…”

Genetic structure of Galium cracoviense (Rubiaceae): a naturally rare species with an extremely small distribution range

“…It is lower than the average reported for endemic plant species (U ST = 0.26, Nybom 2004), and is moderate to low as compared against the range of values obtained for endemic plants using AFLP fingerprinting: for example, Medicago citrina, U ST = 0.18 -0.55 (Juan et al 2004), Hieracium eriophorum, U ST = 0.09 (Frey et al 2012) or Astragalus albens, U ST = 0.01 (Neel 2008). The rather low U ST value may reflect, in part, the small size of the overall distribution area (Reisch and Bernhardt-Römermann 2014).…”

A botanical Christmas stocking

“…() vs. Vereecken et al . ()] and to provide supporting information for conservation management decisions (Asmussen‐Lange, Maunder & Fay, ; Blackmore, Gibby & Rae, ; Ennos et al ., ; Frey et al ., ; Zhang et al ., ), and these subjects are well represented in this issue. Three papers focus on Asian taxa: Guicking et al .…”