The silent extinction: climate change and the potential hybridization-mediated extinction of endemic high-mountain plants
Most global-warming models predict an altitudinal movement of plants. This upward migration of lowland species will surely result in contact with related species inhabiting high-mountain ecosystems. We propose that an overlooked consequence of this upland movement is the possibility for interspecific hybridization between narrowly endemic alpine plants and widely distributed lowland plants. Genetic swamping due to introgressive hybridization might even lead to the genetic extinction of the endemic species, without any apparent detrimental demographic effect. Unfortunately, this phenomenon has long been ignored in the ecological literature, probably because is widely assumed that the ecological effects of climate change are more detrimental than its genetic effects. We tested our idea by searching for human-induced hybridization in a worldwide hotspot biodiversity, the high-mountains of the Sierra Nevada (south-eastern Spain). About 25 % of the endemic flora is already hybridizing in these mountains, mostly with widespread lowland congeners. Some species are even already threatened due to genetic swamping. It is thereby urgent including in future conservation agendas a protocol for detecting and monitoring positive and negative effects of genetic swamping mediated by climate change in high mountains and other sensitive ecosystems.
KeywordsAltitudinal movements Global warming Introgression Plant conservation policy Sierra Nevada
We thank two anonymous reviewers for improving a preliminary version of the manuscript, and to Matthew Clarke and David Nesbitt for reviewing the English. This study has been supported by Junta de Andalucía (P07-RNM-2869, P11-RNM-7676), CYTED (COCAMGLOINBIEMO) and MONTES Consolider-Ingenio (CSD2008-00,040) Grants to JMG and Junta de Andalucía (P08-RNM-3811, P11-RNM-7538) Grant to AGM. MA was supported by BES-2007-14206 Grant from Spanish Education and Sciences Ministry.
Conflict of interest
The authors declare that they have no conflict of interest.
- Arnold ML (2006) Evolution through genetic exchange. Oxford University Press, OxfordGoogle Scholar
- Bañares A, Blanca G, Güemes J, Moreno JC, Ortiz S (2003) Atlas y libro rojo de la flora vascular amenazada de España. Dirección General de Conservación de la Naturaleza, New MadridGoogle Scholar
- Blanca G, López MR, Lorite J, Matínez MJ, Molero J, Quintas S, Girela MR, Varo MA, Vidal S (2002) Flora amenazada y endémica de Sierra Nevada. Consejería de Medio Ambiente, Junta Andalucía, SevillaGoogle Scholar
- Cox CB, Moore PD (2010) Biogeography: an ecological and evolutionary approach. Wiley, HobokenGoogle Scholar
- Coyne JA, Orr HA (2004) Speciation. Sinauer Associates, SuderlandGoogle Scholar
- Engler R, Randin C, Thuiller W, Dullinger S, Zimmermann A, Araújo MB, Pearman PB, Le Lay G, Piédallu C, Albert CH, Choler P, Coldea G, De Lamo X, Dirnböck T, Gégout JC, Gómez-García D, Grytnes JA, Heegaard E, Hoistad F, Nogués-Bravo D, Normand S, Pusças M, Sebastià MT, Stanisci A, Theurillat JP, Trivedi MR, Vittoz P, Guisan A (2011) 21st century climate change threatens mountain flora unequally across Europe. Glob Change Biol 17:2330–2341CrossRefGoogle Scholar
- IPCC (2007) Climate change 2007: impacts, adaptation and vulnerability. Contribution of working group II to the fourth assessment report of the intergovernmental panel on climate change. Cambridge University Press, CambridgeGoogle Scholar
- Morgan JAT, Welch DJ, Harry AV, Street R, Broderick D, Ovenden JR (2011) A mitochondrial species identification assay for Australian blacktip sharks (Carcharhinus tilstoni, C. limbatus and C. amblyrhynchoides) using real-time PCR and high-resolution melt analysis. Mol Ecol 11:813–819CrossRefGoogle Scholar
- Pauli H, Gottfried M, Dullinger S, Grabherr G (2003) Assessing the long-term dynamics of endemic plants at summit habitats. Alpine biodiversity in Europe. In: Nagy L, Grabherr G, Körner C, Thompson DBA (eds) Ecological studies. Springer, Heidelberg, pp 195–207Google Scholar
- Pauli H, Gottfried M, Dullinger S, Abdaladze O, Akhalkatsi M, Benito JL, Coldea G, Dick J, Erschbamer B, Fernández MR, Goshn D, Holten JI, Kanka R, Kazakis G, Kollár J, Larsson P, Moiseev P, Moiseev D, Molau U, Molero-Mesa J, Nagy L, Pelino G, Puscas M, Rossi G, Stanisci A, Syverhuset AO, Theurillat JP, Tomasell M, Unterluggauer P, Villar L, Vittoz P, Grabherr G (2012) Recent plant diversity changes on Europe’s Mountain summits. Science 336:353–355PubMedCrossRefGoogle Scholar
- Rieseberg LH, Wendel JF (1993) Introgression and its consequences in plants. In: Harrison RG (ed) Hybrid zones and the evolutionary process. Oxford University Press, Oxford, pp 70–109Google Scholar
- Tauer CG, Stewart JF, Will RE (2012) Hybridization leads to loss of genetic integrity in shortleaf pine: unexpected consequences of pine management and fire suppression. J For 110(4):216–224Google Scholar