Résumé
Continental-scale assessments of 21st century global impacts of climate change on biodiversity have forecasted range contractions for many species. These coarse resolution studies are, however, of limited relevance for projecting risks to biodiversity in mountain systems, where pronounced microclimatic variation could allow species to persist locally, and are ill-suited for assessment of species-specific threat in particular regions. Here, we assess the impacts of climate change on 2632 plant species across all major European mountain ranges, using high-resolution (ca. 100 m) species samples and data expressing four future climate scenarios. Projected habitat loss is greater for species distributed at higher elevations; depending on the climate scenario, we find 36–55% of alpine species, 31–51% of subalpine species and 19–46% of montane species lose more than 80% of their suitable habitat by 2070–2100. While our high-resolution analyses consistently indicate marked levels of threat to cold-adapted mountain florae across Europe, they also reveal unequal distribution of this threat across the various mountain ranges. Impacts on florae from regions projected to undergo increased warming accompanied by decreased precipitation, such as the Pyrenees and the Eastern Austrian Alps, will likely be greater than on florae in regions where the increase in temperature is less pronounced and rainfall increases concomitantly, such as in the Norwegian Scandes and the Scottish Highlands. This suggests that change in precipitation, not only warming, plays an important role in determining the potential impacts of climate change on vegetation.
Auteurs, date et publication :
Auteurs Robin Engler , Christophe F. Randin , Wilfried Thuiller , Stefan Dullinger , Niklaus E. Zimmermann , Miguel B. Araújo , Peter B. Pearman , Gwenaëlle Le Lay , Christian Piedallu , Cécile H. Albert , Philippe Choler , Gheorghe Coldea , Xavier De LAMO , Thomas Dirnböck , Jean-Claude Gégout , Daniel Gómez-García , John-Arvid Grytnes , Einar Heegaard , Fride Høistad , David Nogués-Bravo
Publication : Global Change Biology
Date : 2025
Volume : 17
Issue : 7
Pages : 2330-2341
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Biogeographic delineations within the European temperate mountains remain poorly understood, as there has been little effort to assemble and analyze vegetation relevés covering Pyrenees, Alps, Carpathians and Balkans altogether. Our study tackles this issue by focusing on the widely distributed alpine acidic grasslands dominated by Carex curvula. Cluster analysis of more than 800 vegetation relevés revealed the European-scale spatial patterns of vascular plant diversity in these alpine grasslands. The geographical distribution of floristic clusters was partly congruent with the physiography of European mountains. Southern European ranges (Southern Balkans and Pyrenees) exhibit a high level of endemism and corresponding floristic clusters are well separated from the others. Marked floristic similarities between the Easternmost Alps, the Carpathians, and the Northern Balkans (Stara Planina) supported a major floristic boundary that runs through the Austrian Alps and that is likely the legacy of a shared Quaternary history. Within the Alps, floristic clustering was mainly driven by ecological drivers and not geography. This paper presents the first detailed study of spatial patterns of species distribution within the European Alpine System, based on a comprehensive analysis of within- and between-community species diversity. It shows that the quantitative analysis of large and consistent data sets may question the traditional delineations of biogeographic regions within European mountains.
Auteurs, date et publication :
Auteurs Mihai Puşcaş , Philippe Choler
Publication : Flora - Morphology, Distribution, Functional Ecology of Plants
Date : 2025
Volume : 207
Issue : 3
Pages : 168-178
Catégorie(s)
#CNRS #Lautaret #UGARésumé
Alpine glacier variations are known to be reliable proxies of Holocene climate. Here, we present a terrestrial cosmogenic nuclide (TCN)-based glacier chronology relying on 24 new 10Be exposure ages, which constrain maximum Neoglacial positions of four small to mid-sized glaciers (Rateau, Lautaret, Bonnepierre and Etages) in the Ecrins-Pelvoux massif, southern French Alps. Glacier advances, marked by (mainly lateral) moraine ridges that are located slightly outboard of the Little Ice Age (LIA, c. 12501860 AD) maximum positions, were dated to 4.25 ± 0.44 ka, 3.66 ± 0.09 ka, 2.09 ± 0.10 ka, c. 1.31 ± 0.17 ka and to 0.92 ± 0.02 ka. The ‘4.2 ka advance’, albeit constrained by rather scattered dates, is to our knowledge exposure-dated here for the first time in the Alps. It is considered as one of the first major Neoglacial advance in the western Alps, in agreement with other regional paleoclimatological proxies. We further review Alpine and Northern Hemisphere mid-to-high latitude evidence for climate change and glacier activity concomitant with the ‘4.2 ka event’. The ‘2.1 ka advance’ was not extensively dated in the Alps and is thought to represent a prominent advance in early Roman times. Other Neoglacial advances dated here match the timing of previously described Alpine Neoglacial events. Our results also suggest that a Neoglacial maximum occurred at Etages Glacier 0.9 ka ago, i.e. during the Medieval Climate Anomaly (MCA, c. 850-1250 AD). At Rateau Glacier, discordant results are thought to reflect exhumation and snow cover of the shortest moraine boulders. Overall, this study highlights the need to combine several sites to develop robust Neoglacial glacier chronologies in order to take into account the variability in moraine deposition pattern and landform obliteration and conservation.
Auteurs, date et publication :
Auteurs Melaine Le Roy , Philip Deline , Julien Carcaillet , Irene Schimmelpfennig , Magali Ermini
Publication : Quaternary Science Reviews
Date : 2025
Volume : 178
Pages : 118-138