Détail de l'auteur
Auteur Philippe Choler |
Documents disponibles écrits par cet auteur (6)
Affiner la rechercheChanges in taxonomic and functional composition of subalpine plant communities in response to climate change under contrasting conditions of bedrock and snow cover duration / Richard Michalet in Journal of vegetation science, 35 (2024)
Titre : Changes in taxonomic and functional composition of subalpine plant communities in response to climate change under contrasting conditions of bedrock and snow cover duration Type de document : Numérique Auteurs : Richard Michalet ; Blaise Touzard ; Gilbert Billard ; Philippe Choler ; Gregory Loucougaray Année de publication : 2024 Article en page(s) : e13253 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Diversité botanique
[CBNPMP-Thématique] Changement climatique
[CBNPMP-Géographique] Alpes françaisesRésumé : Questions
We assessed interactions between climate change, bedrock types and snow cover duration on the trajectories of taxonomic and functional composition of subalpine plant communities. We predict (i) an increase in species richness on siliceous bedrock due to a reduced competition and a decrease in richness on calcareous bedrock due to increasing drought stress; (ii) decreasing snow cover duration should induce a higher shrub encroachment in hollows as compared to ridges; and (iii) increasing growing season temperature should induce taller sizes and more conservative growth traits, in particular in hollows.
Location
Subalpine belt of the Grandes Rousses mountain range, southwestern Alps (France).
Methods
189 vegetation plots were sampled in 1997 and 2017–2018. The duration of snow cover was assessed during two years in 1995–1997 and five functional traits were measured on 108 species in 2021. We performed multivariate analyses, quantified community-weighted means (CWM) of traits and used ANOVAs to detect responses to local-scale factors and changes in snow cover, temperature and precipitation since 1997 according to a nearby meteorological station.
Results
Overall, taxonomic composition weakly changed and changes were more dependent on the position of communities along the snow cover duration gradient than on their bedrock type. The abundance of drought-tolerant species increased at the border of hollows and there was, over all communities, a slight increase in the abundance of dwarf shrubs and tall herbaceous species, a strong decrease in short herbaceous species and, thus, an overall decrease in species richness. There were important overall changes in CWM of size traits, in particular leaf area which increased the most in hollows irrespective of bedrock types.
Conclusion
In this subalpine site the effects of decreasing snow cover duration overwhelmed the effects of bedrocks, which may explain the overall increase in competitive species and decrease in species richness.
Identifiant : DOI : 10.1111/jvs.13253 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=155440
in Journal of vegetation science > 35 (2024) . - e13253Michalet, Richard, Touzard, Blaise, Billard, Gilbert, Choler, Philippe, Loucougaray, Gregory 2024 Changes in taxonomic and functional composition of subalpine plant communities in response to climate change under contrasting conditions of bedrock and snow cover duration. Journal of vegetation science, 35: e13253.Documents numériques
Consultable
article (2024)URL
Titre : Climatic drivers of greening trends in the Alps Type de document : Imprimé Auteurs : Gianluca Filippa ; Edoardo Cremonese ; Marta Galvagno ; Michel Isabellon ; Arthur Bayle ; Philippe Choler ; Bradley Z. Carlson ; Simone Gabellani ; Umberto Morra di Cella ; Mirco Migliavacca Année de publication : 2019 Article en page(s) : 1-15 Catégories : [CBNPMP-Géographique] Alpes
[CBNPMP-Thématique] Relations climat-végétation
[CBNPMP-Thématique] Changement climatiqueRésumé : Since the 1980s, vegetated lands have experienced widespread greening at the global scale. Numerous studies have focused on spatial patterns and mechanisms of this phenomenon, especially in the Arctic and sub-Arctic regions. Greening trends in the European Alps have received less attention, although this region has experienced strong climate and land-use changes during recent decades. We studied the rates and spatial patterns of greening in an inner-alpine region of the Western Alps. We used MODIS-derived normalized difference vegetation index (NDVI) at 8-day temporal and 250 m spatial resolution, for the period 2000–2018, and removed areas with disturbances in order to consider the trends of undisturbed vegetation. The objectives of this study were to (i) quantify trends of greening in a representative area of the Western Alps; and (ii) examine mechanisms and causes of spatial patterns of greening across different plant types. We show that 63% of vegetated areas experienced significant trends during the 2000–2018 period, of which only 8% were negative. We identify (i) a climatic control on spring and autumn phenology with contrasting effects depending on plant type and elevation, and (ii) land-use change dynamics, such as shrub encroachment on abandoned pastures and colonization of new surfaces at high elevation. Below 1500 m, warming temperatures promote incremental greening in the transition from spring to summer, but not in fall, suggesting either photoperiod or water limitation. In the alpine and sub-alpine belts (>1800 m asl), snow prevents vegetation development until late spring, despite favorable temperatures. Instead, at high elevation greening acts both in summer and autumn. However, photoperiod limitation likely prevents forested ecosystems from fully exploiting warmer autumn conditions. We furthermore illustrate two emblematic cases of prominent greening: recent colonization of previously glaciated/non vegetated areas, as well as shrub/tree encroachment due to the abandonment of agricultural practices. Our results demonstrate the interplay of climate and land-use change in controlling greening dynamics in the Western Alps. Identifiant : DOI : 10.3390/rs11212527 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148069
in Remote sensing > 11 (2019) . - 1-15Filippa, Gianluca, Cremonese, Edoardo, Galvagno, Marta, Isabellon, Michel, Bayle, Arthur, Choler, Philippe, Carlson, Bradley Z., Gabellani, Simone, Morra di Cella, Umberto, Migliavacca, Mirco 2019 Climatic drivers of greening trends in the Alps. Remote sensing, 11: 1-15.Documents numériques
Article (2019)URLGenetic introgression as a potential to widen a species' niche : insights from alpine Carex curvula / Philippe Choler (2004)
est un tiré à part de 101 (1) - 01/2004 (Proceedings of the National Academy of Sciences of the United States of America)
Titre : Genetic introgression as a potential to widen a species' niche : insights from alpine Carex curvula Type de document : Tiré à part de revue Auteurs : Philippe Choler ; B Erschbamer ; Andreas Tribsch ; Ludovic Gielly ; Pierre Taberlet Année de publication : 2004 Importance : 171-176 Langues : Anglais (eng) Identifiant : DOI : 10.1073/pnas.2237235100 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=131256 Choler, Philippe, Erschbamer, B, Tribsch, Andreas, Gielly, Ludovic, Taberlet, Pierre 2004 Genetic introgression as a potential to widen a species' niche : insights from alpine Carex curvula. Proceedings of the National Academy of Sciences of the United States of America, 101(1) : 171-176.Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité 13854 C Tiré à part Centre de documentation Tirés à part Consultable Documents numériques
Article (2004)URL
Titre : Long livestock farming history and human landscape shaping revealed by lake sediment DNA Type de document : Imprimé Auteurs : Charline Giguet-Covex ; Johan Pansu ; Fabien Arnaud ; Pierre-Jérôme Rey ; Christophe Griggo ; Ludovic Gielly ; Isabelle Domaison ; Eric Coissac ; Fernand David ; Philippe Choler ; Jérôme Poulenard ; Pierre Taberlet Année de publication : 2014 Article en page(s) : 3211 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Enjeux de conservation des lacs d'altitude Résumé : The reconstruction of human-driven, Earth-shaping dynamics is important for understanding past human/environment interactions and for helping human societies that currently face global changes. However, it is often challenging to distinguish the effects of the climate from human activities on environmental changes. Here we evaluate an approach based on DNA metabarcoding used on lake sediments to provide the first high-resolution reconstruction of plant cover and livestock farming history since the Neolithic Period. By comparing these data with a previous reconstruction of erosive event frequency, we show that the most intense erosion period was caused by deforestation and overgrazing by sheep and cowherds during the Late Iron Age and Roman Period. Tracking plants and domestic mammals using lake sediment DNA (lake sedDNA) is a new, promising method for tracing past human practices, and it provides a new outlook of the effects of anthropogenic factors on landscape-scale changes. Identifiant : DOI : 10.1038/ncomms4211 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=150974
in Nature communications > 5 (2014) . - 3211Giguet-Covex, Charline, Pansu, Johan, Arnaud, Fabien, Rey, Pierre-Jérôme, Griggo, Christophe, Gielly, Ludovic, Domaison, Isabelle, Coissac, Eric, David, Fernand, Choler, Philippe, Poulenard, Jérôme, Taberlet, Pierre 2014 Long livestock farming history and human landscape shaping revealed by lake sediment DNA. Nature communications, 5: 3211.Documents numériques
Article (2014)URL
Titre : Observed long-term greening of alpine vegetation-a case study in the French Alps Type de document : Imprimé Auteurs : Bradley Z. Carlson ; Monica C. Corona ; Cédric Dentant (1976-) ; Richard Bonet ; Wilfried Thuiller (1975-) ; Philippe Choler Année de publication : 2017 Article en page(s) : 1-12 Catégories : [CBNPMP-Géographique] Alpes françaises
[CBNPMP-Géographique] Parc National des Ecrins
[CBNPMP-Thématique] Changement climatique
[CBNPMP-Thématique] Relations climat-végétationRésumé : We combined imagery from multiple sources (MODIS, Landsat-5, 7, 8) with land cover data to test for long-term (1984–2015) greening or browning trends of vegetation in a temperate alpine area, the Ecrins National Park, in the context of recent climate change and domestic grazing practices. We showed that over half (56%) of the Ecrins National Park displayed significant increases in peak normalized difference vegetation index (NDVImax) over the last 16 years (2000–2015). Importantly, the highest proportional increases in NDVImax occurred in rocky habitats at high elevations (> 2500 m a.s.l.). While spatial agreement in the direction of change in NDVImax as detected by MODIS and Landsat was high (76% overlap), correlations between log-response ratio values were of moderate strength (approx. 0.3). In the context of above treeline habitats, we found that proportional increases in NDVImax were higher between 1984 and 2000 than between 2000 and 2015, suggesting a slowing of greening dynamics during the recent decade. The timing of accelerated greening prior to 2000 coincided with a pronounced increase in the amount of snow-free growing degree-days that occurred during the 1980s and 1990s. In the case of grasslands and low-shrub habitats, we did not find evidence for a negative effect of grazing on greening trends, possibly due to the low grazing intensity typically found in the study area. We propose that the emergence of a longer and warmer growing season enabled high-elevation plant communities to produce more biomass, and also allowed for plant colonization of habitats previously characterized by long-lasting snow cover. Increasing plant productivity in an alpine context has potential implications for biodiversity trajectories and for ecosystem services in mountain landscapes. The presented evidence for long-term greening trends in a representative region of the European Alps provides the basis for further research on mechanisms of greening in alpine landscapes. Identifiant : DOI : 10.1088/1748-9326/aa84bd Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=148066
in Environmental Research Letters > 12 (2017) . - 1-12Carlson, Bradley Z., Corona, Monica C., Dentant, Cédric (1976-), Bonet, Richard, Thuiller, Wilfried (1975-), Choler, Philippe 2017 Observed long-term greening of alpine vegetation-a case study in the French Alps. Environmental Research Letters, 12: 1-12.Documents numériques
Article (2017)URL
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